I have being a loyal contract customer of MTN SA Their network is bad in our area

I have being a loyal contract customer of MTN SA Their network is bad in our area. Always down and no network service. I cancelled my contract once the 2 years were up. They are still debating my account I cancelled over email in writing and I called their call center but they are still debating my account. Their agents are useless. Can't do their jobs properly. Need to employ competent people. I am on pay as you go but they still want to charge me for contract. Does not make sense. Highly frustrated with them and communicating with the agents.