Not cancelling contract since July

<p>Beginning July 2016 I cancelled a contract with Vodacom that has not been in use. I have since called them three times to cancel the same contract, but I still receive charges on my billing??? What on earth must I do to get this done properly? Im paying for something that has not been used for months, and keeps on paying for it? Is that the way Vodacom is doing business???</p>