Deutsche Telecom here, anyone living in germany will laugh right now. Those clowns still cannot write my name right, and I've been their customer for years. I correct it every time they send me anything, each time they epologize, say they'll fix it and its still wrong. It has been wrong since I handed the dumbass in their store my ID-card. Yes, thats right, they don't even get my name right. Their salesclown did not manage it to write down my name right, while looking at my ID-card.
One other classic was their hardware. I plugged the ensemble together like it said in the manual - nothing worked. I started experimenting, until I found a combination that did - and was nothing like what their manual said. The blasted router overheated frequently and was a general pain until I bought another one and threw it away. To think I paid money for their piece of junk...
The one thing I really, really hate them for is the contract period: every 24 months it is renewed to another 24 months. So I was pissed at them for a number of reasons, the biggest one being their ****ty hardware, and wanted to get rid of them... waited reluctantly until the time was up, stuffed a precisely phrased sheet into an envelope and sent it via certified mail to their HQ. The letter came back, with a stamp by the post-service: addressee would not sign. So they didn't want to sign that they got my ******* letter. Alright, so I marched to their store, listened to their clerk telling me he knew nothing, and got their local boss, who then proceeded to tell me the correct adress for the damn letter. Another certified mail, so the clowns couldn't tell me my letter did not arrive, and off it went again. A week later I got a reply, saying that I missed the "Three Moths Advance Period" to terminate my contract... basically I would have had to send the crap at least three months before the 24 months were up, and thus was stuck for another period, At that time I paid about 50€ a month for 2mbit, and other providers charged half for triple that speed. So I called their callcenter, one of these hellish monstrosities with waiting-music and "If you want to murder our operator, press one."... after spending quite a bit of money on listening to their idiots telling me they knew nothing and their ****ty music (for 25 cents a minute) I finally got someone competent who told me I could upgrade my speed to a newer contract-system within their company. As that meant I would still pay more money than with other providers, but at least it was cheaper than the old one, I did, and now am in a new 24-months-trap.
Conclusion: the whole provider-business is a rotten nightmare filled with incompetents and perfidious traps hidden behind footnotes in 2pt font at the edge of the universe. And the Deutsche Telecom, being a recently privatized company, is the king of them all. Whatever you do, avoid them.