MTN Refuses to cancel my contract for over a year now

I am disappointed in MTN, i have been with MTN for over 12 years, and now i have been trying to cancel my contract for over a new year, and no luck, instead there's a R35 being deducted every month, and i do get any other service from MTN, no data, no airtime, nothing, and when you call to cancel or send email, you get no response. Please do me a favor MTN and cancel my contract, and refund me all my money, i am at my wits' end, with all the abuse. CANCEL MY CONTRACT AND PAY BACK MY MONEY!!!!!