Pathetic service from legal department

I have been handed over by MTN during covid period without even 1 phone call only calls from the debt collection company. I have paid it up and they cleared my name on clear score and without informing me they handed me over again dont know for what reason. I assume it was because of my email I've send them cause they cept on billing me for a contract that already expired. I have been trying to get through to the legal department but they cut me off or you hang on forever. I want this sorted out cause I can't even open up a clothing account just because of mtn's pathetic service.