INCREASING MONTHLY PREMIUM

HOW IS IT POSSIBLE THAT YOU CAN BUT A CLAUSE IN A CONTRACT THAT I SO IMPORTANT TO ADVISE A CONSUMER IN ORDER FOR HIM TO MAKE A RATIONAL DECISION I MEAN THIS MUST BE EXPLAINED IN EVERY CONTRACT THAT IS SIGNED BY A CLIENT UP FRONT. WHY IS IT THAT WHEN I CALLED VODACOM ALL THE CONSULTANTS COULD REFER YOU TO A CLAUSE REGARDING THIS INCREASE ONLY AFTER IT TOOK PLACE NEVER EVER MMENTIONED IT BEFORE AND THE PEOPLE THAT WORK AT THERE BRANCHES DONT INFORM YOU. HOW CAN I PAY FOR SOMETHING THAT WAS NOT AGGREED UPON WHEN I SIGNED I WAS TOLD THAT WILL BE MY PAYMENT THIS MY CONTRACT EXPIRE NOW THE CHANGE THAT IS NOT FAIR I HAVE 2 CONTRACTS WITH YOU I AM UNHAPPY I WANT TO CANCELL THEM BEFORE THEY EXPIRE AND NOT PAY ANYTHING I HAVE A RIGHT TO CHANGE MY CONTRACT THE SMAE WAY YOU DID I THINK THAT IS FAIR PLEASE ADVISE