I sold a legitimate software item on ebay, the buyer didn't pay after 2 messages and ~7 days after he won. Finally he responds saying he accidentally bid. I was not happy, so I opened a case against him and told him I'd drop it after 4 days so I could get my listing fee back (and so he would get the strike through for the transaction). He agreed to pay if I dropped shipping costs, which I did. He paid- I mailed the item- now, several days later he opens a claim saying the item is fake. I am just fuming because he clearly just didn't want to pay. Any advice?