Has it been more than 32 days since the sale? I'm assuming it has then it is too late for you to open up a non payment dispute which would then give you back your final valuation fees and issue the buyer a strike. You may as well try it though. Go to your sold item. Over on the RHS of screen click on the drop down menu and click resolve a problem (or similar) it will then bring up a new page select I sold an item and haven't been paid. If that fails try contacting ebay through the customer support link at top of page.

I would relist item, buyer has had plenty of time and not communicating.