Nu debt management

I have made a payment to nu debt management on October 8 2025 due to mtn that has handed me over to them. MTN also listed me under ITC for some reason and that’s how I got to know about my listing. I recieved a paid up letter from mtn(nu debt management) stating that I do not owe them any moneys and I have paid up my debt. I’m trying to clear my name at Experian and Transunion but mtn keeps saying that I still owe them the amount I payed because nu debt management has not yet made payment to them. I’ve contacted them numerous times regarding this matter and I’ve spoken to many supervisors but no one seems to know or be able to assist me in this matter. They keep telling me to wait and call back.