incorrect billing

I just upgraded my internet contract.<br> been using it and month isnt over as yet...and vodacom says that i ran out of data.<br> i took a 2gig package, but yet on my modem device it shows i have only used 1gig.<br> <br> now vodacom cant verify this data...as i am saying it is incorrect.<br> instead of them prooving me wrong, i must proove them wrong...by subscribing to their itemised billing.<br> which i am not prepared to pay an addition R25 for.<br> <br> What a *******