Very Unhappy Loyal Customer

I was offered a special unlimited contract by vodacom which I was told will cost R1199 only(not more or less) per month. Before accepting this contract I asked the telesales agent (***asi) about 3 or 4 times to confirm the price knowing that calls are recorded and he insisted yes. Now I have a bill for R1658.97. I've now called the call centre numerous times(6) since the 1st of November and get pushed to every department but with no resolve. They now tell me I have to pay for a device which was not told to me in the recorded conversation. Obviously mislead me to get the sale. Vodacom can you Please respond and resolve as I do have a total of 7 contracts with you. 2 on business and 5 on personal and I won't hesitate cancelling them all as they reach end of contract period and switch to another network.