i got robbed of a £100 in the same position as yourself, i sent a wheel back which was buckled, only for the seller to sat he never recieved it so he wouldn't refund my money, i contacted the courier, who produced a signature to say it was delivered, the seller then sent me his signature that was photo'd from a bank card, completely different, after contacting the couriers again, they said someone down the hall in his block of flats signed for it, as they know him. the seller denighs any knowledge of this. couriers wouldn't pay me out either. the couriers did some more investigation and found out this person pulls this trick on a regular basis, i contacted ebay, and they didn't want to know either, as far as i know the fella is still doing this on ebay,,,, his ebay name was alfaofficechairs or something similar........i was furious, but he's down on the south coast, and i know the type, other than bashing him up, you wouldn't get anywhere.
my advice is to ask the seller loads of questions via email so you have proof. ebay sellers will always lie or tell fibs, and front wheels are always dodgey, to many wheelies and crashes.....
