These related Help pages may answer your question:

• How do I request a Final Value Fee credit?
  After filing an Unpaid Item dispute, you can request a Final Value Fee credit. For specific instructions on requesting a Final Value Fee credit, click the link above. . . .
• How do I keep track of my fees and payments?
  You can view your account activity (such as fees, payments, and credits) by clicking "My eBay" at the top of most eBay pages, and then clicking the "My Account" link on the left side of the page. You'll find a number of different ways to view and sort your account information. . . .