Unhappy Vodacom customer

On Friday, 13 December 2024 this number called me +*** about my contract that I have with Vodacom. Their told me that that my contract is R960 and that she is calling to give me R40 discount I told her that I did not sign for that contract but she insists that my contract is R960. After sometime I called Vodacom customer care and their informed me that my contract were changed from my initial contract to R960. This is the second time that I encountered such thing from Vodacom, and when I called to complain they can't assist me or help me.