Standard Bank credit card

I had a credit card with Standard Bank which was handed over to Velile Tinto and associates in 2020.I was offered a settlement amount to clear my account in 2021 which was done.I received a confirmation letter from the attorneys that the account was settled in full.In 2022 I received a phone call and emails from MBD attorneys who were now collecting on the same Standard Bank account.The letter was issued them on several occasions. Standard Bank now wants me to pay the amount that was supposed to be written off as the settlement was paid as per the email I received and that Istill have in my possession. The service received by Standard Bank is terrible as they are of no help.