FNB credit card fully paid and request to close sent BUT they dont want to close it

I requested FNB credit card department for a settlement amount on the 15 August 2019 and them paid it off immediately and requested them to close it. The consultant then put the request through and told me that a consultant will call me to confirm closure.

I then received a call from Nonhle to confirm closure and I confirmed that I want the credit card closed after she went on and on trying to convince me to keep it. I told her to close and she then said she will and send the closure letter.

Now i get an sms from FNB stupidly saying that my new balance as off 16 September is R75. When I called FNB they say I told Nomhle that I want to keep it.

FNB is a **** and they are trying to make money in a wrong way. I want the credit card closed and i want the letter proving it NOW.