********** contract sold

Against my better judgement, I agreed to take a contract (no device included, just contract) for 24 months. Sales agent sold me a 10Gig contract, at a discounted price of R 499 pm. With unlimited minutes. To my surprise, first 2 debit orders go off, almost R1000 per debit order. Phoned the customer care - opened an incident. Was to receive feedback within 48 hours. Needless to say, did not get any feedback, had to call to find out that Yes, the agent did indeed sell me this contract. And that they were still investigating. 1 week later, I had to call again to get feedback. Once again, case still being investigated, after they confirmed via the recordings, that the agent sold me the contract at a discounted price. Apparently, they cannot apply the discount to contracts taken out telephonically, only in store. Even though they have recordings of the sales agent selling me this contract. I have to keep waiting, until they finish their investigations, and decide whether the contract is valid. They sold me this contract? Is it not legally binding? Pathetic customer service. Sales agents chasing commission I suppose, selling ********** contracts to customers.