Fidelity ADT money hungry but no human compassion

If I could give this company less then 1 star I would. I've been cancelling the same contact for almost a year now. I have spoken to Zanele in their accounts department and I have emailed their supervisor Neval, but still each month they try to deduct money from my account and then tell me I have a payment in arrears. But in the same breath can't answer a simple question like why is my contract still not cancelled?