I have the same issue today I have had in the past. When I checked the other day I had only used 4 gig of my 10 gig plan and I hardly use more than 6 gig each month. Was doing nothing except watching TV today and just went to log on and it is very slow. Checked usage and it is all gone. So I called and they tell me I used 6 gig today between 5:00 am and now which is impossible seeing I haven't been on. I have been with them for 3 years now and have had this issue before with them and they have terrible customer service. I guess it is time to shop around again my contract is over. They told me to call back tomorrow to see when my data was used because they can't be specific today. Can't tell me how it was used but can sure shut it down fast. What a joke. Don't want to buy a gig for $10 and have it disappear in 2 minutes.