FNB Not Closing My Paid-Up Account and NOT Issuing 'Paid-Up Letter'

I am terribly frustrated and so disappointed with FNB. I was offered a settlement discount for my cheque account overdraft facility which I paid on the 13th of April 2021. To date the account has not been closed and I have not received a 'Paid Up Letter'. I have been calling almost every week and I am told to keep an eye on my email, and nothing has materialized. This is so frustrating and I am being delayed in building up my credit record, whereas I have paid the monies due.