Staff that is not doing their job

In November 2022 I paid up my Nedbank cheque account and I was given a paid-up letter by Ntshepi Molefe from Bankcol. In February I went to Nedbank to open a cheque account and I was told that I owe an amount of R1200 for the cheque account, the same cheque account that I paid up and closed. It turned out that Ntshepi did not send the paid-up letter to Nedbank. I gave Nedbank the letter to prove that the account is paid up. On the 26th of April 2023, I got an email from Nedbank telling me to settle the same cheque account, I sent them the letter I got from Ntshepi and I told them in February this matter was also settled. Nedbank said they will deal with it. Yesterday the 8th of May, I found out that the same cheque account is still reflecting as unpaid with interest. Firstly Bankcol didn't do their job in November by failing to send the paid-up letter to Nedbank and now Nedbank after receiving the letter in February from me and in April, still failed to remove it. This is affecting my credit profile and they don't care. I am disappointed in Nedbank. How many times should I send the paid-up letter? why is the account still reflecting on my name? Clearly you don't care.