increase of monthly installment by sms

i have 4 contracts with Vodacom, 2 contracts expire end of june 2015. I have received a sms today on both tablets on contract that my subscription will be increased from R99 to R109 per month as of end of May 2015. upon calling Vodacom today I spoke to a consultant telling me to go the website and on the terms and conditions there is a fine print stating Vodacom can at anytime increase my contact subscription. should this not be told to me as a client when I take out the contract? I am seriously considering taking my contracts to another service provider. Vodacom will loose a lot of clients. they cannot just send an sms telling me as a client it will be increased. I have agreed to pay a fixed rate every month on these contracts at Vodacom and was considering upgrading both contracts but if this is the case then I will rather take on another service provider that do not just increase my contacts because the fine prints was not stipulated in bold to me from the start, this is totally **************** to all the Vodacom clients. I would like for someone to take this up as I am not the first person I know got this message.