If a refund I issue is accepted, are the fees from the original transaction credited to my account?

You can refund the entire amount of a transaction or portions of it. The default refund period is 180 days from the transaction date.

If you refund a payment for goods or services, there are no fees to issue the refund, but the fees you originally paid as the seller are not returned to you. The amount of the refunded payment will be deducted from your PayPal account.
 
To learn how to issue a refund after 180 days from the original transaction, click here.

To learn more about variable and fixed transaction fees, click Fees at the bottom of any PayPal page.