Vodacom ****med me

I called vodacom on 12/10/2023 to ask for cancellation of my contract. Spoke to a guy who promised to reduce my subscription and give me a cellphone if I agree with the new/reduced amount,which I did. Den 3 weeks later the device/cellphone which we talked about didn't come and when I enquired they said its out of stock, I then called and spoke to someone who said we can change the device/cellphone, that was on the 30th October 2023, which I agreed. Then on November month end the debit amount was not changed, it was even more than what I was paying before my initial call to cancel. I called vodacom a couple of times and no I was told that its too late to dispute and that there is nothing they can do at this stage. I really feel ****med by this big company. And when I tell them to listen to the conversation of the 12/10/2023 and the one of the 30/10/2023 they all tell me that they will escalate the mater and I will get feedback, and they dont give me any reference no.