Vodacom Contract Nightmare

I opened up a contract with vodacom for their R299 deal for 80GB during the first week in October. Once I activated my sim card the problems began. Not only were they ********* about the promotion, but also once I had activated my sim and got registered on the vodacom app I found that already 2GB of data were gone and I didn't even use it yet as I was on wifi. Not only that but the sim they gave me did not have 4g service only up to 3g lte which is very slow and pathetic. when I tried to test the speed by doing a google search, not only did it take very long but 600mb of data was already gone as well. Totally unbelievable. I called in that same week to stop the contract so that my contract sim can become a prepaid one instead. I was told that naturally I would not have to pay for the month or anything else, and would get a confirmation of this change within 3 working days. It is already the second week and not only have I gotten no feedback but the contract fee for the month has already been taken from my account!!! I called again regarding this and was told that no cancellation or reversal has been done at all, and whatever money that was taken will be credit......None of this has been done. My contract has not been stopped, nothing has been credited and no feedback or update has been given to me. Vodacom how can you be so quick and efficient in taking my money when you have not carried out a decent service? I want this sorted out immediately!