Hello,
If you refunded via the Paypal account, then yes, you are still liable for eBay's fees, but more importantly, you have given your account a defect.
Send the buyer a cancellation request. They need to accept this for your to retrieve your Final Value Fees. If they decline you are stuck with the fees, if they ignore the request, you can close it yourself, after 10 days, and again your FVF are refunded.
