Sold An Item 30th December No Payment Yet

Hi All I sold an item on 30th December 2013 Buyer asked for 2 weeks to pay which I gave him 15 th Janruary item still not paid I openen a NPB with Ebay.. I contacted the buyer today and asked hm when payment can be expected. I received message that he "Says" he is in hospital and will not be out for another week. My query is How long can I let this ride before Ebay say I cannot  claim a Final Value Fee Refund.

Paddy