Credit card account not closed

In December 2019 I asked for a settlement amount regarding my standard bank credit and they emailed it to me a paid the whole amount I was even charged an extraR72 because I was closing my account. I sent them proof of payment and asked them to close the account because I had another account with them when I closed it they didn’t so I asked them nicely on the email to close this one as I didn’t want the repeat of what happened. The next thing I receive a statement saying I’m owing I fowarded them the email and they said I had to call the insurance department first before they can close my account, I asked them how is that possible because I paid the settlement amount and asked them to close the account and I didn’t get a reply in January 2020 my account was debited I called them and they said my account was still open I asked how is that possible and I was taken from pillar to post until my airtime depleted. I send them emails I even send an email to complaints with no response. Yesterday I received an email from them telling me that if I don’t pay the account it will accumulate I am so disappointed in Standard bank