Billed for subscription that I did not subscribe

I am being billed for content services that I don't know about. I queried this with Thembela at Vodacom customer service and he says it's for a service called Speedkeeper. I told him that he must reverse that charge because I did not subscribe to his service and he refused. All he did was cancel the service. Vodacom needs to reverse this billing or I will take this matter further. I am with Vodacom for many years, but if this is the attitude of customer service then I will consider legal action if need be.