I am pretty sure I found your closed auction on and it looks like you've got $5.75 plus some elbow grease tied up in the chip. Yes, I would definitely say the seller should have disclosed that this chip had what a lot of people would consider to be a problem.

A question comes to mind; are you happy with the chip as it is now that you've cleaned it? If you are then I'd move on but if you're not then I'd send the seller an e-mail. This seller has a 100% feedback rating so I'm guessing that he probably wants to make sure his customers are happy and it stays at 100%. That might mean taking the chip back or giving you some sort of refund. Maybe he has a whole rack of the chips and he can just send you out a replacement. Give that a try.

Cheers!
Bill