I recently sold a motherboard on eBay and the douchebag who bought it is claiming that I sold him a faulty item. He has started a return claim even though I stated that no returns were available (simply to avoid cases like this with idiots who don't understand how to install and use computer hardware properly). He also seemed in a big rush to receive it which leads me to believe that he might be attempting some sort of swap out fraud.
Is there anything that I can do about this? I have reported him to eBay for misuse of their buyer protection program but other than that it looks like I'm primed to get shafted and it's really annoying.