False information, and lying staff

I called vodacom to cancel my contract. And i spoke to a consultant called Siyabonga Madida. He persuaded me to take out an upgrade and said i will pay R249. But when i check the invoce now it is saying a different amount of R363 which is not what i agreed to. I have tried calling the cancellations department to cancel this piece of ******* contract and no one seems to want to help me. They keep saying they are sending a message to siyabonga madida and he will call me. He has not called me. I regret ever doing business with this pathetic company.