account debited twice

On 1/9/15 went to absa to arrange once off amount debited to an fnb account. My account was debited 2x without my authority to the value of R15 000. I furher more <br> Went back twice to have Matter sorted out Absa personel oferted no guarantee no reference number given to me, no turn around time to expect matter to be sorted out, no next step to take if matter was not sorted out in x amount of time. Was in turn told that \ mam there is nothing we can do about it it was the system which went of twice