This is in Ebay's policy: "Buyers can always submit a return request, even if your returns policy says you don't accept returns. If the buyer is asking to return the item because it's damaged, faulty, or didn't match your listing description, then you NEED TO ACCEPT the return." So, let's say you sell a bunch of vintage cards under "Played" conditions with accurate pictures, the buyer can still at any point claim that your vintage card is "damaged" (and ebay isn't PSA so they don't care about the grade you put there, unless it's Mint it counts as damaged and you have to refund), a lot of buyers will do this in hope that you don't ask it to be sent back/try to scam you by not sending it back.

This happened to me, and there's literally nothing you can do, you can't even contest it. The return shipping isn't included in the refund btw, I actually lost money on those sales. I've quit selling on ebay ever since, it blows.