FNB deductions borders on theft!

I can't believe how FNB is still allowed to deduct whatever they want, whenever they want from customer's accounts. I have had many arguments with them about this over the past few months, the most recent of which I received a notification simply stating that my Covid 19 cash relief loan debit order will be processed on 15 Dec. I sent them an email on 30 November stating that I did not agree to this, and that I do not give permission for the debit order to go off earlier. Yet, they still went and did it and subsequently charged me a penalty fee because I didn't have money in my account. How is it possible that a financial institution is getting away with things like these, over and over and over again. Not only have I lost all faith in the bank. With so many of the same complaints about one institution and nothing happening, the regulating bodies are as much to blame.