Guys, I buy and sell a lot of stuff, here, there and everywhere in between...
Rule Number 1: always use a picture or pictures of the actual item offered for sale; barring that, if no pictures are available at least be forthcoming and say so.
Rule Number 2: make sure to accurately describe to the best of ones ability what you are offering; barring that explain that you are not an expert or perhaps refer to an expert for a more detailed description
Rule Number 3: exchange as many pictures, additional information etc be it by emails, snail mail, telephone calls, carrier pidgeon etc
Rule Number 4: offer a money back guarantee if the customer is not satisfied or offer to rectify hte deal and make good on it.
I must agree with all the other posts, that you Sir have done wrong, make the rest of us decent guys look bad and generally give people another reason to be skeptical and make honest guys lives harder.
I would be pissed off too, rightfully so.