Fnb unauthorized deduction

I am extremely upset with their service, due to the previous incident, they deducted money from my account without authorization, and their response was, a lot of people have been complaining about it for years and they don't have a solution.

And then 30/07/2019 I called them and ask that they do not deduct my installment amount from my account, reason being my mother paid money into my account to clear the dept, after several phone calls which they have on record, they promised me that they will refund the amount, 7-10 working days, because they deducted the installment, after I asked them not to.

15 days later I had to call again. We are now on 22 days

What is a person supposed to do? This is unacceptable, because I am being provided with incorrect information.

They said the refund was processed, and it takes 2 working days to reflect, we are now on the 3rd working day of the 22 days which I have waited for this problem to be resolved, I have been banking with fnb for a long time, this was not the expected level of service I was expecting from them.