Unauthorised debit order that keeps debiting

I am currently frustrated with FNB for their inability to help me with an unauthorized debit order that I have been reporting for months. The best that they can do for me is to always reverse the money back into my account but the following month the same debit order goes off. I really am frustrated and with this lock down i cant be moving up and down to go reverse the debit order again for March. In February the debit order was R69.00 and for March it is R444.00, I have been banking with FNB for over 22 years but i really feel this will drive me to close my account with them if that will mean i will finally have peace of mind.