I think you should contact them and let them refund your payment, (like they said they would). Give them a time-line, let them know they have ~1 week (or whatever time duration you see necessary) to refund your payment. After that, let them know you will contact your CC company to pursue a refund or charge-back.
IMHO... you should strongly consider the fact that the item may have been stolen in transit. Personally I have had two low dollar items stolen from me by either US or foreign customs, as the shipment crosses the border. By the time I get the package, its been opened, poorly re-taped with contents missing.
For my transactions I do not believe the seller/trader scammed me, I honestly believe it was customs helping themselves to the contents inside. One time, they sent me an empty box.
I have a nephew in Quebec, who has shipped/sent dozens of items internationally. Over half the items he has tried to send/receive have been stolen or partially stolen by international/Canadian customs. He pretty blatantly told me once that he does not trust customs offices anywhere. I generally have the same viewpoint.
Its unfortunate, but thats the mind-set I have been conditioned to have.
Good Luck, I hope it all works out.