Vodacom outrageous data charges

When I upgraded my contract to red vip unlimited- the sales person didn't explain the contract detail in full. He only said that I have unlimited minutes and SMS . And 5 Gig of data - that was more than enough because I normally only use 3 Gig per month - I have no idea that I must buy data bundles when finish - I mean if my 5 gig is finished why isn't it finished ???? Why is Vodacom still running your data and charging you ridiculous rates I mean R5600 for 9 Gig - yes that's what happened to me my data was finished and I didn't realized that it is still running I have never heard of out of bundle rates and have no idea how it works - why can't they say in plain simple tex - \ from now Vodacom will charge you R2 per MB - please reply yes if you understand the t &amp