Bad customer service-The call centre is like a circus

I called cancellations department on the 23/01 and spoke to two agents the first one was rude and I disconnected the line and they never called back 2nd agent Mandisa I requested for her to cancel my contract and continue to use my number on prepaid she kept placing me on mute, telling me the system is offline, after a long time holding for her while she was checking on the system the line disconnected and till today she never called back. What kind of customer service is this? Now I must continue to pay for something that I specifically asked to be cancelled and moved to prepaid