Unauthorised debit order

I got a notification for a debit order that went off my account without my knowledge or authorisation. I contacted the call centre which informed me to go to a branch. I went to a branch and they told me that there isnt much they can do about it. She said she would try blocking it but if it doesn't work I would have to go to the bank every month to reverse it after it is debited. I found this very disappointing as I've been using Absa for over a decade and trust that they keep my account safe. If people can take money from my account and I can not do anything about it then what security is the bank providing to me as a customer? I was told that if the debit orders do not stop I would have to change my account number, that is such an inconvenience and would have expected the bank to have a better solution. I was also informed that I'm not the only one with this problem and everybody has it, that shows that there are security issues if everyone is having this problem.