FNB Customer service

I had troubles with a company that was debiting my account when I never authorized a debit mandate. I contacted the ***** service and I was told that they can't do anything from their side. I then stopped the debit order and contacted the debit department to confirm whether the company would still be able to debit my account and all they said is that I would have to wait for the end of the month to see whether they debit my account or not