MTN theft

I am trying to cancel a data contract I no longer need. In store I’m told they can’t help me I must dislike 135. My voice line is Vodacom so I have been trying for 3hours to no avail. I then tried to email both retentions & customer care to do the same - no response after 5 days. This is disgusting with no way to cancel & the debut orders keep going off. This is effectively theft as I see it!