PATHETIC SERVICE/CREDIT PROVIDER

I HAVE A PERSONAL LOAN WITH NEDBANK & MY LOAN TERM IS DUE TO END THIS OCT/NOV 2016 - I HAVE MISSED ONE INSTALLMENT & THEY TRIPLE DEBITED MY ACCOUNT AS WELL AS THE ARRANGEMENT FOR THE MISSED INSTALLMENT. I SPOKE TO MANY CALL CENTRE AGENTS & THEY SAYS ITS A SYSTEM ERROR DUE TO THE EASTER HOLIDAYS. I HAVE REQUESTED A REFUND FOR MY EXTRA BANK CHARGES AS NEDBANK TOOK OUT MONEY THAT WAS FOR OTHER ACCOUNT DEBIT & NOT REFUNDING ON TIME. I HAVE FAXED MY BANK STATEMENT SHOWING THE EXTRA BANK CHARGES DUE TO NEDBANKS ERROR & THEY HAVE REJECTED MY REQUEST. I THINK ITS PATHETIC AS IT IS THEIR ERROR THAT MY OTHER DEBITS DID NOT GO OFF AS NEDBANK DEBITED THEIR MONEY IN ERROR OF 3 DEBITS GOING OUT. ITS NOW ONE WEEK & THEY HAVE NOT REFUNDED ME.