Let me see if I have this right...your buyer resold the item they bought from you?? And now they've gotten a refund from you?? By reselling, they assumed posession of the item.
Call ebay and keep calling til you get someone who can straighten this out (it may take a couple of calls
If you have a store you should already have access to a phone number...otherwise go to HELP and type in 'password' (that will always bring up a "call us" link) Try that and good luck!