No help!

Nudebt Debt Management is useless. I was handed over to them in 2023 by MTN due to struggling at the time. I made an arrangement, paid the amount they wanted and forwarded proof of payment. This year I started receiving emails again. I have phoned them and they could not see any outstanding amount... the emails continued... I phoned again and the rudest person answered the phone. Telling me to phone MTN. How can I phone MTN while they are the people harassing me with emails. I have sent numerous emails back to the email addresses they provide with the proof of payments for 2023, but obviously I do not get any response from them. Totally unacceptable and unprofessional rude people.