Disregard of my settlement amount by ABSA and failure to close the Credit Card account

I have paid ABSA its settlement amount wrt the Credit Card account I had with them. In paying the credit card account I even over paid the settlement amount. I instructed them to close the account and pay me back the over paid amount that is due to me. To this day the account is still active and the over payment of the settlement amount is not yet paid back into my bank account. I have been phoning ABSA since the 13th of May 2023 and throughout this week (15.05.23-18.05.23) but to no avail as they have failed deliberately so to accede to my repeated instructions. Not even a reference number was provided to me for my settlement instruction though I paid both settlement amounts that were quoted to me. I have been in contact with ABSA National Office from the onset in dealing with my settlement payment. So, the branch is not involved in the entire saga. It's the Head Office that has placed me in this predicament. They must just close the account as in yesterday and pay me back all the money that is due to me.