Disappearing data, facing brick wall

<p>I bought 1GB of data from Vodacom, switched on my modem and in less than 1 minute I was told all the data has been used up! I looked at their itemised billing online which was quite frankly a load of ******* (saying in less than a second I was using 200MB of data, with 5 reports like this). Faced a brick wall on the phone with them basically saying I had definitely used the data despite my modem saying I used less than 20MB. I've switched to Cell C and using the same device my 1GB has lasted over a week. Quite simply they are *****ing data and making up how it's been used in **** itemised billing. STAY CLEAR. My sim card has gone in the bin.</p>