unexplainable data usage/missing data

My data usage with Vodacom has doubled in the last 2 months - my actual internet usage has not increased and Vodacom refuses to acknowledge the problem or provide me with a detailed breakdown of where my data is going.<br> My monthly bills have doubled for no reason and Vodacom refuses to investigate and threatens to suspend my account unless I blindly accept the costs and pay.<br> <br> On one occassion, the 2 GIGS of data I had just purchased was used up overnight, despite the fact that my computer was not switched on once during that period. I called Vodacom and they flat-out refused to investigate.<br> <br> I cannot get past their call centre operators, who refuse to transfer me to a manager or supervisor and will not provide me with an explanation more detailed than \this is your usage"? I am also not able to reach them via email channels."""