Money vanished with no trace

I bought an item using payflex account and PAID UP my account on the 2nd of May buy FNB attempted to debit on the 5th and didn't get anything and for that I lost R180 on penalties and then R920 came through from my own sources then R522,25 was out of my account with no trace. I got a missed call from some Chad guy from FNB after I sent through screenshots of all transactions, assumed he wanted to help but I sent emails again hoping someone would help but no response till today. What an awful experience FNB, after so many years of service?