Vodacom upgrade ****

I recently went into a Vodacom store to upgrade my contract that I hadn’t upgraded since 2014. I was then informed that my account has already been upgraded by a person named Molepo without my knowledge. I have been trying to reverse the was then advised to call Vodacom online to check if there aren’t any phone recordings showing that I agreed to the upgrade. I wa Athens called by a consultant from elite mobile confirming that the investigation done showed no record of the upgrade having been done with my consent. I’ve been trying to reverse the upgrade but I’m being sent back and forth. The last consultant advised that I need to get email an affidavit to Vodacom o line and only then will they start the investigation of my case. What I don’t understand is if it’s been proven that I didn’t agree to the upgrade being done why is it my problem to get it reversed when this is clearly an inside ****.