debit order

As I have been with FNB for a long time I expected to to be protected by the bank. Debit orders with no authority are being debited from my account even though I have called the call center and spoke to Marcus and also been to the branch. The worst part is that I am not even able to reverse the debit orders. It has gotten to a point where I will be reporting fnb and also the other company as well as change bank accounts which is something I have avoided for a year. I wish them luck.