Is Cell C trying to make money?

I have had a data contract with Cell C for a number of years. In the past when the contract expired, the amount increased, but to an acceptable amount. This year, it increased from R274.00 in August to R374.00 in September the next month. Then it increased to R710.00 in October, which is ridiculous. I am sure if I can view the contract, the amount if R710.00 doesn't appear anywhere in the contract. My understanding is that the amount needs to go back to the amount quoted before the discount. I have noticed that another client has the exact same problem with the exact same amounts. To top it all, I still have to pay it for another month. I can't belief that a company can do this. If they have tried calling me about the contract, none of the numbers showed that it was from Cell C. I don't answer unknown numbers. I would have signed a new contract, but unfortunately, I can't see myself entering into a contract with a company that would stoop so low to make money. I am very disappointed. I also had to call Cell C 3 times before I could "pass" my authentication. I will tell everybody of this bad experience.