Cancellation of contract

Last year September (2014) my contract for a 3 gig modem expired and to date ive been batteling to cancel it. Last year I called the TOLL FREE number and while I was busy verifying my details with the lady my phone just cut off. That phonecall took ALL of my airtime. After numerous failed attempts my father tried to cancel it this year. A few weeks ago he spent between 14-20 minutes per turn on the phone waiting for someone to answer. He then emailed headoffice on 30 April 2015 to which we have recieved no answer. He got an email acknowledgement from Vodacom but to date no one has contacted him. Now please tell me WHAT THE **** I STILL NEED TO DO TO TO CANCEL THE CONTRACT!!! We even went to a vodacom shop to which they said that they can do nothing we must just be patient and keep on calling! This is exactly the reason why we went to MTN. You are the most useless and *********** company i have ever dealt with! I expect a reimbur*****t for the 9 months I unwillingly had to pay due to your incompetence. I would appreciate it if vodacom can contact me ASAP in this regard!