MTN AND NUDEBT ***********, disgusting service

On 2023-01-25 I have paid an amount of R4422 for settlement on closure of my MTN contract that I was holding for over 20 years. On 2023-02-25 I noticed that the account was credited and not cancelled as per the documentation of the previous month. I forwarded a querry without assistance, I've send a new querry. They requested my personal details (although having my account number etc) still no feedback received. I then started with cancer treatment and forgot about this matter. March 2025 I started receiving threatening emails and sms messages from Nudebt about my account. I've send them countless proof of payments as well as the cancellation letter without them even acknowledging any of it! I again send an email to complaints at MTN just to say they are sorry for the long wait for assistance but I must email their legal department for assistance. I've send two emails.... NO RESPONSE! I've since found that this number was reallocated during 2024 to a wifi router contract belonging to a very nice lady. I have also never renewed this contract, I have paid the settlement amount given by MTN to close this account, how do I owe them that same amount? I am now threatened with blacklistings on the credit bureau for something I paid and MTN failing to do their part! This treatment, after being a customer for longer than 20 years, is disgusting to say the least. And Nudebt is just as *********** and arrogant