Try to resolve this with the buyer directly. If he does not want to do anything about it, eBay has a conflict resolution system you have to go through. Its a bit of a pain and takes some time but in the end, it helps you out. eBay's conflict resolution is more biased toward the buyer (which hurts honest sellers) so more often than not, you'll get your way. Since eBay owns paypal, it'll be pretty seemless getting your money.