Falsified subscription Charges on upgraded Contract

I would like to launch a complaint regarding my subscription charges for my number. I upgraded in May 2018 for a deal that included + additional 1GB data pm for 24 months and I just realized that I am actually charged 50% on it. But the catalogue does not specify that it at a discount not free. I even asked the consultant at the fourways mall Vodacom and he had confirmed that it was free. I would like to have this rectified because Vodacom cannot falsify information about the deals provided. It is unacceptable.

After I complained and called the consultant at the store he admitted to the fact that they as consultants thought it was free however now vodacom told them its not free. so That's why I am being charged. when I escalated the matter he then denies that he said it. he says he told me on the day of the contract that this was to be paid for.