Unauthorised Debit order

Called in the call center line in order to reverse an unauthorised Debit Order on 1 July 2019 at 14:38 got hold of a consultant who goes by the name of Siya who told me that they can't reverse the debit order and he kept on asking questions that he knows the answer to. So I asked him to let me speak to his manager, he told me that I have to call back in... like really? Why do I have to call back in, in order to speak to his manager when he's the one who doesn't want to listen to a simple request of reversing a debit order that I did not authorize! I am definitely leaving FNB