Credit card problem after cancellation.

On 15 August 2023 I paid the settlement amount on my credit card. I phoned Discovery Credit Card and explain that I paid the amount, and that I want to close the account. The reason I gave is that I am a pensioner and I want to settle most of my accounts.The lady said that the call was recorded. She assured me that the account will be closed when I put down the phone. Yesterday I received. Sms show outstanding statement R92.17 How is that possible?