Frustration after ********** upgrade

In the beginning of 2017 I saw that my 2 Vodacom data contract accounts increased considerably. I went to the Vodacom store in Cresta Shopping Center where I was informed my two data contracts where upgraded to 2 x Iphone 7's. Although I never authorized the transaction (and thus FICA was never properly done by Vodacom) I had to go to the police station and make an affidavit that I did not authorize the transaction. During this time Vodacom kept on billing me over R1500 a month although I made it clear it was **********. I then had to put up a massive fight to get my money back. I again went to Cresta where I asked that the contracts get cancelled as the sim cards for my data were replaced and thus not working only to find out Vodacom has kept on charging me for those old contracts after the ********** ones where cancelled and would not let me cancel my contracts until I settle the amount (again over R1400). I paid this, signed the forms and I then told my bank to stop all direct debits as the contracts were cancelled. Only to start getting phone calls from Vodacom threatening me as I am not paying my account. I have tried over 10 times to explain to the "customer service" person that I cancelled the contract only to be told that I upgraded and cannot cancel. I have called back and have emailed and all I am being told is to call ********** which again leads down the same path. In my view this is theft and harassment as Vodacom did not do due diligence and is now threatening my credit-ability on as a "non-payer". This is truly by far the worst customer service experience I have ever had in my life and will never take out another Vodacom contract or recommend them to anyone else.