Does USPS show as delivered? If yes eBay is going to give you a hard time.
Your best bet is Amex.
I bought an item on eBay recently. After 3 weeks no show I opened a case. After the buyer didn't respond I esclated the case. Ebay then tells me to wait another 10 day.
I was fed up, I filled a dispute with Amex, instantly I was refunded.
On day ten the buyer finally ships.... I contacted Amex that the item came and since they refunded me where should I mail it to. They said they will advise me. A few days ago I got a letter saying the case is closed....
Free item!