Cellc team leaders needs to be trained throughly they need to understand what is the difference between a leader

I am so disappointed by the service i received from cellc. Last month i was billed an amount of 348.99 when i called in to enquire regarding that i was told that i am being charged for a late fee of 70zar, called in to dispute the charge however i was told that there's nothing that will be done. Yesterday i received an sms from cellc stating that i am gonna be billed 348.99 again i called in again spoke to tshepo from customer service he told me that the account was in arrears that is why am being charged that amount. I requested to speak to his supervisor named Mavis who is based in Johannesburg sage building. Mavis said she will call me at 14:30 but she never returned my call i then called around 15:15 and i was told that mavis knocked off at 14:30. I called in today again to request for a supervisor i spoke to her while speaking to her the call got cut.