Horrific FNB service

I have had an amount of R129.99 a month debited from my account for a few months, reference TTMS. I have not authorized this transaction. I soon went to FNB to find out what exactly is happening. The consultant told me that this is a ***** debit order and there nothing she can do. She tried to dispute it but I was only allowed to dispute one transaction. I have never been reimbursed or even assisted with this matter. I have asked the consultant if this could happen again and she says yes it can, if the person uses a different branch code. I then asked her how do i prevent this, her response was to just monitor my account and then inform FNB. I do not expect service this bad from a reputable bank such as FNB especially because of the ridiculous bank charges.