They replied promptly. The headphone is considered defective and i can return it, they'll even refund the return postage charges.

Returned, refunded.

Outstaniding! I am surprised they refunded the postage. They must have better C/S policies in the UK than Canada. Are you going to try another pair or move on to another headphone altogether?

Amazon.co.uk only refunds the return postage if the item is damaged / defective or was delivered because of an Amazon error.
The Amazon.ca returns policy is worded differently. I would contact CS to clarify.
I'm wary of buying a V6 again, and i'm wary of trying something delicate like the Creative Aurvana Live (read about wire failures). I feel like i figured out the sound of the V6 and am ready to move on but only to something durable.
I'd mostly like a durable IEM under $150. Checked Innerfidelity's wall of fame, Head-fi's summer 2012 guide (pdf), recommendation threads. Often i hit a wall because of significant discrepancies in prices and availability between the US and UK, or frail designs.

For the price point you are hard pressed to find anything better than an IEM. The only trouble with them as you have noticed is their fragility, and that pretty much means looking at something with detachable cables. Or as i did with My Etymotics, coat the cable driver joint in an epoxy to relieve the strain. If you are looking for an interim solution and are moderately handy I would suggest picking up a set of the Phillips ear clips model is 4700 I believe, (The box mine came in have no model number) they sell for about 10 dollars here. Pop off the clips and get any kind of headband on them that will exert moderate pressure on the ears, and their sound easily rivals that of the V6 in every way except the bass thump you get from the closed earcup. Properly sealed to the ear these little wonders have an exceptional detail and enough low end response for any but the serious basshead. For the 10 bucks plus whatever it costs for a headband (I initially used a piece of 1/2 inch flat aluminum bar stock and blu tacked the drivers on, careful to not block the bass ports at the back) they are an unsung little gem completely ignored in the marketplace. And at that price if you lose them on the tube or they get squashed your not going to cry.

For the price range i conversely found that full size headphones (mostly circumaural) have the best price/performance ratio, the V6 being the prime example. The Shure SE215 has detachable cables and too many Amazon reviews say that while they sound good they fail in months.
I forgot to say i only like in-ear and circumaural headphones, for their comfort and isolation (if they're closed). Which Etymotics do you have?

I have a pair of early 90's ER4S's and i would not give them up for anything. They are actually the only ones that I have kept for that long. When you fit them out with the Comply tips they are a hard little item to beat. You can occasionally find the Shures cheap on Ebay so it might be an idea to find a pair there. If yo are committed to circumaural then the Sennheiser HD 25's are hard to beat. Although the cognicenti really lean toward Fostex T50's right now as the bargain of the century if you have the ability to mod them. I'd have to agree with that but currently am looking at the T20 as I keep hearing that they are a better phone. Both are around the 90 dollar mark over here. I would love to have a go at the Klipsch X10 i's but durability seems to be a real issue with those as well.

The Sennheiser HD25 is supra-aural. It ($200 -> £140=$210) and the T50 ($100 -> £140=$210) and T20 ($80 -> £100=$150) are overbudget, hit the wall again. EU import customs and VAT (19% in the UK) raise prices.

Ouch. You folk are still getting dinged heavily, I had thought prices had stabilized in Britain in the past decade. Do you get hit for VAT on personal purchases from overseas as well? I was going to suggest the M Audio Q40 but it is about 20 dollars more than the T50 here so more than likely well over the limit there. Have you considered any of the Asian products such as the Superlux 681 or HD330?

I don't exactly know the applicable law. When i ordered RAM from OWC - who operate in the US - i wasn't charged the US sales tax but when the FedEx plane landed in my country a FedEx rep called me that customs opened my package and charged me 27% VAT on the declared price plus even on the shipping cost (both were on the included invoice) - I knew before i ordered. Same would go for ordering some rare Sony from Japan or anywhere outside the EU. This can be a real dealbreaker on expensive stuff like a $2200 mac as it would cost me $2800+shipping or buy it in my country for the equivalent of $2900.
When I ordered from the UK, i was charged the 19% UK VAT (collected by the seller) but no customs in my country because it was a commerce inside the EU.
I didn't even know about Superlux, i'm going to read the reviews.

Strange rules abound. Here if it comes in via mail we may or may not have an inspection which results in 6 dollars + whatever duties and taxes may apply. Some items are duty exempt and some are not and it seems the customs people vary greatly in what they deem dutiable. We have a14%GST (goods and service Tax) which is much like VAT. If we have a carrier bring it in Such as Fedex or UPS we get charged a customs clearance fee which is userous sometimes 40 dollars and then they collect the tax on top of that. It really pays here to have things come via post as it invariable costs very little and the inspections on small items are fairly rare.
The Superlux are getting very decent reviews. Bang for buck they are hard to beat. I was set to pick up a pair of 681s when a deal on a pair of T20's came up. I still want to own a pair of the 681 and more than likely the 330 or 660 closed back phones. That will have to wait. Here is a link to a German Dealer http://www.thomann.de/gb/superlux_hd660.htm

Having used the V6 -being my first full-size- i found that that kind is only convenient when i'm sitting at my desk using the laptop. I watch a lot of movies in the bed or listen to music on the go, so an IEM would be universally useful for me.

Why buy a Superlux over a V6 or CAL? (if price doesn't matter as long as it's under $150)

The IEM market is so huge right now it's almost impossible to know where to start.If you are not heart set on a balanced armature set then I'd suggest the Head Direct RE0 (check reviews), Probably no better budget earphone other than the monoprice, but the monoprice units are hit and miss as to whether they will fit your ears.

Is there even an IEM under $150 that sounds at least as good as the V6 or the CAL?

There are dozens of under 150 dollar IEMs that fill the bill. http://www.head-fi.org/t/478568/multi-iem-review-273-iems-compared-vsonic-vc02-added-02-24-13-p-641 Here is the official thread.
The RE0's and Monoprice units although not stylish are hard to beat for price/performance . If I had to start all over and was picking one to try out as a first experience it would be the Monoprice unit as it is so low cost there is very little risk. That gets you something very decent to listen with and you can make a long term decision on IEM or Banded phones later.http://www.monoprice.com/products/subdepartment.asp?c_id=108&cp_id=10823#1082303. The 8320's are great as are the somewhat tacky 8322. Between the two I can listen to the 8322's forever as they have such a pleasant presentation and are easier to fit in my ear (if you go to the local pharmacist they sell silicon putty ear plug material for swimming and this makes a great little seal). I have Sennheisers I paid 10 times as much for and use the Monoprice units instead of them. If I am on the tube I don't have to worry about being out several hundred dollars if I lose or break them as I do with the Etymotics.

My first IEM worthy of mentioning was the $100 Sony MDR-EX90 which i used in the past 6 years until i couldn't mend it anymore this january; so this won't be my first experience, and i'm looking for something at least that good.
Having read hundred+ reviews of dozens of IEMs and headphones i'm increasingly getting the impression that it's probably not even worth buying an expensive-ish IEM if they break every few months unless i constantly remind myself to take extreme caution using them, or i have hundres of dollars to burn on IEMs each year.
As an interim solution since january i've been using the V6 + a $10 Sony EX10 (until of course i returned the V6).
Do you call it "tube" in Canada?

Yes in Toronto the subway is called the Tube, in Montreal anglos call it the tube Francois call it the Metro. My mistake I thought this would be your first shot at an IEM. I was literally in shock when I broke the ER4's way back when. Luckily when I called Etymotic they asked for the serial and told me they were one of the first units sold so they covered the whole repair and shipping. As I mentioned I did put epoxy blobs over the joints to prevent that problem ever happening again and they are still going strong. Right now the Klipsch X10's are going for about 90 bucks here (they were 350 not a year ago) and that is a mighty tempting deal. They are excellent. I have not heard of any real problems with it and the design looked rather strong. I would probably run a bead of silicon over the cable to housing juncture on any IEM I bought these days just to be sure. The other alternative are the Bose. I keep a pair of the mark II units around simply because the fit with the contoured silicone insert is wonderfull, I wish more companies would use that type of fit. The sound is not a crisp or punchy as the X10 but easily as good as the v6 when you have the right insert fitted. They can be a little fragile if mishandled but I have not had any issues with them.

I have updated the review, after having owned the second V6.

First off. If you are still looking for an in ear. Try the BLOX earbuds. Hands down the best audio value out there. Amazing truly amazing sound for Fifty bucks.
Second. I cannot believe the quality control issues you are seeing with the V6. That is just outrageous. In your shoes I would be sending those pics off the the Sony offices in your country and ask a simple "What Gives?" question. I should think they would be more than willing to take responsibility for this mess.