Furious FNB credit card customer

FNB prem credit division took an auto payment from my current account which has caused me to be over drawn! I have paid my credit card min payment and Fnb have still taken money from my account without my premision. I have asked them to cancel the auto payment which they are unable to do. I have asked to speak to line manager who is unavailable and she said I should expect a call as it me 15:45 on a Friday. Monday I will get a call. This is the worst service I have ever received from a company. I will be closing my credit account once it’s paid up and I will be moving my account away from Fnb.