5 Months to cancel a contract???

I have been with Vodacom for MANY years. I had 4 contracts with them at the age of 22 that I was paying an average of R2000.00 for. Now when I would like to cancel one of the contracts that expire in March 2015 in January 2015. I do it over the phone. NO hassles. Still getting billed for it. Called 4 times to cancel/confirm cancellation and no it has not been cancelled. I cant upgrade and I cant cancel. SO WHAT AM I PAYING FOR?<br> I will not pay my account until this is sorted out.