So many ebay listings are listed as new and sealed for games and movies, but like Hawkeye22 said, I would never get a game with an online pass. I have purchased games and movies before in the past, and it was easy to see that the seller just used shrink wrap to seal the game and make it look new. Was there one of those white stickers on the edge of the case that you would find if it was from a retail store? If that was there and it was still intact (not cut or reapplied), then I would say contacting the PSN would be your best bet. If it was absent, cut, or reapplied, I would say you're out of luck and will probably have to buy one.