Cancel Contract

Took a data contract with MTN 2years ago which ended on the 8th of August. I got the wrong package yet was paying the full amount, had to write a complaint on hellopeter for me to be assisted. Now I want to cancel the contract as I do not wish to renew it I’m still given a tough time. I called again today to check if it has been cancelled but to my surprise it hasn’t. MTN really has poor service delivery. Trash network.