Insurance premium being charged 3 years after cancellation

I have been requesting vodacom to cancel the insurance policy on my phone for about 3 years now, every time I call in they first say they can't see my insurance and after fighting with them they say they can see it and will cancel it, and 3 years later I am still being charged for it. By my calculation they have taken well over 4K and I'm pretty sure I would have to get lawyers involved in order to claim a refund, which will cost more than what I'm owed. So Vodacom for the last time, please cancel the handset insurance, I have long lost that phone and you didn't even let me claim for it, you let me block it but when I tried to claim you told me stories.