FNB Connect deducted two debits 4 times

FNB Connect deducted two debits 4 times. Then deducted two of the debits correctly. I contacted them to tell them I had been incorrectly debited 4x to the value of R776. The first consultant got the amount wrong and didn't seem to understand the error. The second consultant was very helpful. However, I followed up again as its January and that money had a purpose. To my surprise, the third agent got the refund amount wrong again and they only logged the refund today. I have been waiting for a week. He initially said refunds take 7-14 days which I was ok with except that they only just logged it now. Then he changed his statement and said it's 7-21 days. If the error is on the bank's side why do I have to bear the financial brunt of it. This is not the first time this has happened to me with FNB. They also erroneously took over R14k which I had to fight tooth and nail for. The consultant was very rude and just directed me to complaints. Without any explanation as to why this error has not been fixed