Mtn sucks

Mtn suspended my line because they say someone changed my method of payment from debit other to cash and now they are making me pay double the amount I usually pay and they are not putting me through to their supervisors nor managers to resolve my problem. Now their internet is supper slow, it always buffering. I can't even get through to their contract call center to follow up on the reference I was given by their unfriendly consultant Nqobile Nkomo. I just don't like mtn now