I got the iPhone 4 and signed me and my mother both up for the 2GB data plan. It turns out we use a lot less than expected. I'm at about 120mb and my mom is at 30mb with about a week left in the month. I use AT&Ts app to check how much I have used and when I checked today it said it could not display it because I had recently changed my plan. I did change my mom's plan to the 200mb plan 2 days ago but I haven't changed mine. I looked to see if mine had been changed as well but it was still at 2gb with no option to change. My moms also has no options to change. I thought that you were able to change your Internet plan as many times as you wanted during the month. I am now unable to change mine even though I have never changed it. I wasn't planning on changing it anyway, just checking how much I had used, but now I'm really annoyed that changing my moms plan has made it so that I can't even view my usage or change my plan. Didn't they say at the beginning that you could change your plan as often as you want to suit your usage?