MTN is a joke. Poor customer setvice!!

MTN does not respond to mails. If you phone you are passed from department to department. They had me as having defaulted om payment. I had no knowledge of this for over 2 years. Eventually did credit check and found i was owing. Paid this small amount over 2 months ago but still waiting for a paid up letter. No one responds, no one responds to mails. It is very frustrating