Insurance charged to account when no authority was given for this

My father upgraded his contract last year and when asked to add insurance on the contract I specifically said no to the upgrade department at Vodacom. After a few months reviewing my dad's invoice I notes that Vodacom has been indeed charging him for insurance. I called Vodacom and they logged a query on the account and provided us with a reference number 1- ********** ********** . They then advised that in the interim we should cancel the insurance which we did. A few days later we received an sms advising that the query was resolved. I then called Vodacom and they advised that I should speak to cell sure. I called cell sure 4 times and everytime the call got cut an no one called back. I would like to know why if Vodacom got the instruction to not add insurance to the contract did they take it upon themselves to just do so and now they are passing the buck to cell sure. I would like all previous amounts paid to be refunded as I did not authorise this an I would like it done by Vodacom and not cell sure as my deal g were never with cell sure to begin with.