FNB DECIDED THAT I HAVE AN OD FACILITY

i USED MY DEBIT CARD AT THE TOLLS AT APPROX. THE END OF MAY 2015. RECEIVED SMS SAYING THAT MY ACCOUNT WAS IN THE CREDIT BALANCE. IN JUNE 2015 I RECEIVED ANOTHER SMS SAYING MY ACCOUNT WAS OVERDRAWN. I CHECKED MY BALANCE IN THE ACCOUNT AND TO MY SURPRISE I WAS OVER DRAWN AND OWED THE BANK R700.00 PLUS MINUS . AFTER CLOSELY CHECKING THERE A FEW CHARGES LEVIED BY THE BANK FOR BEEN OVERDRAWN. SPOKE TO THE BANK AND AM STILL AWAITING A REPLY WHILE INTEREST AND CHARGES ARE STILL LEVIED ON MY ACCOUNT. I HAVE SENT NUMEROUS EMAILS ASKING ABOUT THIS BUT NO AVAIL.