Slow terrible service, failed to close my account

I have been trying to close my credit card and not getting assistance,I requested for a settlement letter on the 25th.03.2025 which was sent to me,I then settled my account and contacted Nedbank as per the settlement letter to close the account,I was informed to pay an additional amount outside the quoted amount on the settlement letter.couple of days letter my account is still not closed I phoned to follow through and was again told to put more money in then received another sms saying my statement cycle is in and I must pay another amount of which I phoned then again because this is really inconveniencing ,I was told to ignore the massage, fast forward my credit card has still not been closed after paying everything that was requested.the account is settled I just want the account closed how difficult is that Nedbank.