unauthorised contract renewal

I had a contract that expired in February 2015. I advised Vodacom to migrate the number to prepaid then I advised to switch off the phone end of February 2015 and switch it back on beginning of March. I did that and assumed that all is well. To my surprised Vodacom billed me again for March 2015. I called cancellation on the 8th of April and I was given reference: s3-82z2u-u8zok and asked to send an affidavit to [Email Removed] I sent an affidavit on the 13 April of which the matter I was told I was referred to ***** dept. I have called Phiwa from retention who refereed to legal which couldn't help, I called Neo from retention who referred me to switchboard telling me that *** is the ***** number. I am so dissatisfied with Vodacom service - they renewed a contract without my approval after I've called and told them to cancel. They have blocked the number and cannot provide any explanation. I have not heard any feedback with regards to my affidavit. I will never ever have another contact with Vodacom. The number in question is ***.