Did you pursue the dispute by message or did you speak to eBay customer
service... I find that if I try to use the automated system for problem
resolution I lose every time... The only chance of a reasonable solution
comes from talking to eBay custom...
Do you have receipts from post office reflecting the trcking numbers the
buyer heisted from you? Perhaps yo0u can submit them to ebay as proof
you are dealing with a scammer!