Sudden price increase.

I have two contracts with Vodacom and have been a loyal customer since cellphones were first introduced in SA.. <br> Suddenly, part way through the contract periods, they advise that they are increasing their prices. This is now an additional expense every month that is not budgeted for and, for some people, may not be affordable. By all means increase the price when the contract is renewed and the customer has the option to not renew. The costs of cancelling a contract are so punitive that most clients will be forced to just pay the increased amount. No doubt this is what Vodacom is banking on.<br> Surely, where there is a contract in place, they can not just do this? <br> If I am unhappy with the increase do I now have the right to cancel my contract without cancellation fees as they have unilaterally changed the terms?<br> What does the CPA say about such a case?<br> No matter what the end result of the client uproar that I am sure is about to happen, I will never trust Vodacom in the future. That is, if I continue to deal with them.