missing data

I was connected to a new wifi device on Monday 21 Sept 2015.<br> <br> I was told I had 10gigs of data to use. I phoned the vodacom careline at midday on Friday 25 Sept 2015 to conform that I had 10gigs, on the same day, after using only 3.34gigs (according to the official mobile wifi app) I was cut off.<br> <br> I phoned the vodacom care line and was told I'd used all 10gigs.<br> This is not possible.