FNB failed to close a settled credit card in 2020

I received an email from SYMINGTON DE KOK INC informing me that my FNB credit card facility will be cancelled, I however settled my credit card with FNB in 2020, I subsequently sent an email requesting them to close the settled credit account as it was reflecting as active on my credit report this was back in May 2020. 2 years later I received an email from the attorneys handling the account that I owe R41000.00 the credit card limit was R18000.00 at the time. I am 8 months pregnant and have been inconvenienced by FNB, I now have to go to the branch and resolve this matter.