It seems Data Usage shown in your app is not real time? How long is the lag? Not sure, a few minutes, a few hours? I would suggest to add a time stamp to it, e.g. "474 MB Used, updated Dec 1, 12:27 ET".
Given the range of responses here (i.e. real time, not real time, delayed somewhat, can't tell, etc.) Public Mobile should revise how the data usage information is presented so it's abundantly clear when the data was updated.
