Sheldon-Been in your shoes before as a seller. Some fool kept promising payment for an item he won and never followed through. If I am not mistaken, eBay will permit you to leave feedback, either positive, negative or neutral for UP TO 30 days after the close of the auction. What I ended up doing was checking the auction time again and left negative feedback for the would be buyer just before the time expired so unless he was online pronto he was stuck with the rating he deserved. I then blocked his user ID from ever bidding on one of my items again. Haven't heard a peep from the fool again and that was over a year ago. Subsequent checking of his user ID showed after I posted feedback he was barraged with negatives during the next couple of weeks so who knows. It's worth a shot if you feel sincerely taken advantage of.