Price increase mid-contract

I have been a mobile contract client with Vodacom for almost 8 years, and I have never experienced such. I have just received an SMS stating that my subscription is increasing from 1 May 2015. <br> <br> This is just madness because I signed a contract that stated that my subscription will be a certain amount for 24 months. <br> <br> I hope Vodacom is prepared to lose millions of clients because of this stupid move. I for one was already fed up with them. this move just put the final nail in their coffin. When the time for my next upgrade comes, i am porting my number, and I am gone. <br> <br> They have just handed clients over to their competitors on a silver platter.