Unauthorized Debit despite Prior Arrangements

Despite sticking to a credit card payment arrangement, FNB card collections just debited my account without my authorization for R7000! When I phoned the card collections department, I was repeatedly told that it will take 5 DAYS for the money to appear in the credit card account. And nothing can be done until the money goes from my FNB cheque account to FNB credit card account. 5 days. I am without that money and they are making interest off it. I was also told that many debit orders have gone off twice on other accounts by the person at card collections. Shocking