Dishonest and ********* Business Practice

I renewed Vodacom data contracts *** and *** with uderstanding as per contract that unused data is carried over from one month to the next, this was always the case all along - to my surprise after 12 months, I just discovered Vodacom has been swindling me and not implementing data carryover as per contract, this is worst dishonesty from Vodacom - the law is clear and Vodacom has also confirmed - data carry over rule is effective. Why is Vodacom misleading & fleecing their loyal customers?