Pathetic service deliver from MTN

This by far is the worst service I received from a service provider, I have been trying to resolve a billing issue due to go off at the end of May from the 1st of May to no avail. I called on the 4th of May and was told a supervisor will call me back, its been 5 working days and still nothing. I called today spoke to a guys by the name of Siyabonga who refused to give me his surname, I asked to speak to a manager he said they not in the office he will escalate. I asked whe I will get a call he said when she is not busy. The level of service is beyond appalling and he thereafter dropped the line in my ear. I want matter resolved before I go to Ombudsman. If you employ people like Siyabonga its no wonder you service is so pathetic. You call me to upgrade and dont discuss fees in full and expect me to just pay you, how is this treating clients fairly. I want a resolution ASAP