Incorrect billing and nothing done about it.

I upgraded my wife's phone ( ********** 169) 10 June 2017, she had a core prime and upgraded to J7. The monthly installment should be R217.49..the first month after the upgrade was the account R647.81 and since then I struggle every month with the account till today.. I phoned Billy at Vodacom Witbank ********** 011, again from 14th May 2018 - June 2018 the account is R452.23. I need to struggle and fight every month for the difference on my account of R234.74.this is unexceptable I don't enjoy having an account with Vodacom on top of this amount that's more every month they just add data bundles to the account without any communication nor did I agree to this data bundles to be added to this account. I requested they must send me proof that I signed any documentation or any voice recording that I agreed to this data bundles that's added every month to this account and thus far no one could assist in this regard, I phoned again last night the consultant who assisted me gave me the ref. 1- ********** ********** to lock my query and no one phoned me to follow up. I am not a happy customer and I have decided that once my contracts reach expiry date there will be no upgrades and currently I have 3x contracts on my name and Vodacom will loose me as a potential customer and more people to follow me and I will change my subscriber. This is not a threat but a promise.