I'd remind him that an eBay auction is a binding contract and he needs to either refund your money in total or re-send the package (depending on your mood). If he indeed has your address correct then he has a valid beef with your postal system - not you. You have upheld your end of the transaction and he should do the same. If selling at a loss was a problem he should have opened the auction at a profitable amount.
Sometimes people amaze me!