miss management and system out of date

I am really getting frustrated and annoyed now, my personal loan was in arrears because of Covid, three separate payment arrangements were made, the arrears were already paid off last month with one of the arrangements but all three of them went through resulting in FNB taking R1000 too much, I phone them to cancel further payment arrangements and have them refund me the excess, and made sure with the agent that the cancellation of the payment arrangements is successful and that it won't happen again, he assured me, aside from that they took double the promised lead time to refund me. This month all three of the previously cancelled payment arrangement went off again a total of R1761 that is not FNB's to take.