Telkom deducting money because the call center agents cannot do there work

Been charged *******ly when my WIFI has been cancelled. Spoke to an agent on the 28th of Feb 2022, was promised a phone call from a manager in 24 hours. It is the 4th off March and still have not received a phone call.... Had to cancel my account a month later then what was originally agreed on in 2021 because the people by Telkom cannot do their work and now I am been charged for bad services. The phone call when my contract as originally canceled was said to be my legal binding contract for fiber. Telkom has refused to give me a copy of this and refuse to understand that my contract was cancelled before but the call center agents cannot do there work .

Why must I be held liable for that?

I would give -10 stars if possible!!!