********** transaction on my credit card account

I made a withdrawal of HK$500=R876 but Standard bank deducted R11876, so R11000 too much. I reported this and they said they will reverse the transaction in 24hrs it was an error. They never reversed the transaction and debited my cheque account with R12000. There was only R1000 available on my Credit card, and cash withdrawal limit is set at R2000/day. My Cheque account is now overdrawn and I have no access to funds since 31st August. My private banker could also not stop the debit when instructed nor resolve the issue until now, its already the 5th of September. So my complaints are, how can Standard bank credit card division deduct more money than available on my credit limit, then not reverse it, then debit my cheque account without authorisation, sound like pure ***** to me. In addition there is R1300 worth of fees for a single withdrawal of R800!