Powerless to vodacom

It took me three months to cancel my contract even though my 24 month contract had already run its course and I should have been on month to month. When Vodacom eventually cancelled my contract I also lost all my contract data and minutes that I already paid for! What happened to the new law that says my airtime is mine to use as I want? Will not be using Vodacom anytime soon. The call centre is frustrating, the level of customer service is poor even in the stores.