Useless and *********** service

I have been struggling with MTN for 2 months now, upgrade was supposed to be done that time, since then 4 MTN staff have phoned me to tell me I am due for an upgrade, so I redid the upgrade with another agent, I was not sent and itemized bill, they raised my debit order to double what I was paying without me knowing what it was for. I have been in touch with an agent Telula (spelling not sure) ***, she has been telling me for almost 2 weeks now she will sort it , now after 2 months of trying MTN staff I have been cut off saying I owe R839, for service I never received, MTN must be the worst provider I have come across, and I worked in the Telecommunications industry for 38 years, I have had it now with MTN I will forward all my communications and complaint to the ombudsman