Why does my phone say offline and how can I check my data usage?

In this situation, you need to call U.S. Mobile and don't tell them, hey, my U.S. is not working, because they won't understand. Just tell them, how much data do you have left?

Please give them a call, and once you finish, call me back.

If they tell you yes, call me back. If they tell you no, ask them to add more data and that's it, okay?