No paid-up received after settlement of the account

Norton Lambrianos Attorneys collected money from me on behalf of Standard Bank credit card that I owed. They offered me a discounted settlement payment which I honoured in January 2020. Then the problem started when I asked for a paid-up letter, where their representative by the name of Wandile Majola rep**** me through email. Wandile Majola on behalf of Norton Lambrianos Attorneys sent me an email, stating that my account with them is settled and my file is closed and also that they instructed their client, Standard bank to send me a paid-up letter but it will only be available after 14 days. Up to now in June 2020, I have not yet received that paid-up letter. All I see in my ITC report is that there is still a remaining unpaid balance. This balance was not there in ITC report a few weeks after settlement of my account. But now about 3 months later the balance just reappeared in my ITC report. Now when I'm phoning the Norton Lambrianos Attorneys, no one is answering the phone and I don't get email replies from them. They used to respond quickly when I was still paying them.