No proactive controls to prevent unauthorised debit orders on personal account

I received an sms with my id number informing me of a debit order that is going to run on my account on the 31. 08.18. I called the number given on the sms for several times and there was no response. When I called Standard Bank to inform them to stop the debit order as I did not authorise it i was told by the consultant Thandi Mali that the bank can not stop it, I will have to reverse the debit order once it has gone through. And that anyone who has my account number can debit my account whether they have proof of my authorising the debit order or not. I'm very frustrated as it means that anyone has access to withdraw my money without my permission and Standard Bank does not have any proactive control measures to prevent this.