Cant Cancel my Contract

My Contract expired in September 2017. It was a data contract.I have sent through the cancellation form in August,September,October and November but my contract is still active. Telkom keeps on charging me although the number is suspended. I have spoken with numerous consultants during the last month and each one say they will escalate it to no avail. I will not pay the outstanding amounts as the cancellation form show on my account (per the call center agent). I am fed up. How difficult can it be to cancel a contract????

This is all the agents that tried to assist me : ********** ; ********** ; ********** ; ********** ; **********

Number in question is : **********