Contract for Credit Card - R4000.00 Approved

I app**** for a credit card at African Bank for R4000.00 it was approved. I have signed the contract, received a card, all fees were taken off by debit order. With the card I tried to withdraw money just to see there is no funds. After a couple of days I contacted African Bank, I was informed that Head Office declined my application. Hey what is this I have signed a contract that legally approved me. I have given them all documentation including the required pay slips. African Bank has already taken the initiation fee, I have a copy of the signed contract, this is contract fee. I demand that this be rectified as soon as possible, if not then this complaint with relevant signed documentation will be handed to the Ombudsman for further investigation as I cannot be held accountable for incorrect procedures or processes at African Bank.