Think twice before entering into a contract with Vodacom

I had a data contract with vodacom when it was time to renew I contacted them(vodacom) to cancel the contract - The lady I spoke to persuaded me to renew the contract with the supply of a tablet .The tablet was dispatched to the incorrect address . I contacted them and they told me they had made a mistake with the address and would rectify the matter. Over a year later paying every month i'm still waiting .So i've tried to cancel this contract without success.