Double Deduction

I have a savings and credit card account. The savings was debited twice, once correctly and the second by mistake. The debiting is a normal transaction as it is to pay of my credit card debt. The issue I have is that FNB charged me a transaction fee for the second transaction and then didn't refund me the fee after they realized the mistake. They have subsequently refunded the second amount to my savings account but not the transaction fee. I have been into the Clearwater branch to rectify the issue but the consultant didn't seem to know how to address the issue.<br> <br> This is the second time such an occurrence has happened to me with FNB.