cancellations logged but not done

I have tried to cancel my Wifi router contract with Vodacom since January 2015. I asked to cancel it due to there not being any signal in my area.<br> <br> They sent a technician to test this and agreed that I may cancel.<br> <br> I have phoned about 10 times since then and my contract is not cancelled. I am still paying for something that I can not use.<br> <br> Was placed on hold again today for 21 minutes and then got cut off.<br> <br> Can someone please help me?!!!