Expensive on upgrade plans now having grief when i want to cancel my contract

My cellphone contract expires en January 2018, I have called in since beginning December to cancel and the agent asked my reason and advised that i can get a cheaper deal for the same phone with better data and airtime plan for much less than what Cell C had to offer. They then asked me to forward the deal to them to attempt to match it for me. After numerous back and forth calling they have not come back to me on a deal match then i asked to proceed with cancellations which they they wanted to do end February because now i only called mid January to cancel. I have disputed this a week ago and still no feedback from CellC. After being a client of theirs for almost 8 years i am disgusted in their service and overcharged tariffs. Before i recommended people to them and now I would rather discourage them from going to Cell C.