Vodacom *******ly activating services I didn't sign up for

Vodacom automatically activaced a damage insurance on my account after 23 months of having a contract with them. Just a month before my contract expired. When I phoned they said the system activated it ( without my consent) they said they will cancell it and refund me,but the next month they again deducted it and I am still awaiting the refund. When I phoned again they said they closed the query and credited me with R131 which was suppose to be credited with R708. When I asked how do they get to that amount they said they don't know. So a contract that was supposecto be R184 per month which I legally signed is now R1210 per month. They are *******ly deducting from my account which my consent. I need to get legal advice,cos this is *******.