MTN refuse to assist even though my contract is fully paid.

I switched bank accounts so had to do my December and January account payments manually, I did the January payment from my Capitec App but since MTN didn't process my payment right, I did it from the MTN Active website in February thinking it would help, only to start receiving SMS'es that i am two months behind in payments. I have the proof of payments and have sent it to MTN on Messenger per their request, since then I've been totally ignored, 7 times ignored in fact. My services have been suspended and my credit score in tatters because of their own inability to respond to or take action with my query.