Astronomical data usage bill.

I have a my meg 300 data bundle contract ***) with R100 voluntary call limit p/m. Average usage on this contract over the past +-1 year 6 months, was +- R450.00 p/m.<br> According to your Customer Care, Vodacom does not interrupt/stop a session while one is busy with it, when the limit is reached. Well that is not true - I have been stopped many times in the middle of sending E-mails, etc. , even before ALL the available cash has been used. In any case, it totally defeats the object of setting a limit in the first place anyway. <br> It is impossible that a 2 gig session could have been registered in 1 day (26 February 2015 @ 6h29 , on a Thursday while on the way to work). This internet ****le is used mostly for E-mails . Even if I give Vodacom the benefit of the doubt regarding this assumed 2 gig session : how in the world can 2 gig cost R2,579.61 ? That means 1 gig cost R1,289.81 ? Please explain urgently!