I Have A Droid X with Page Plus but 3g does not work why?

i just recently got page plus on my phone.....but 3g does not work on it. It stopped the same day on 11PM that night.........why? I got the unlimited plan.....i think it was 40 for unlimited im not sure but yeah it was working fine! but then it stopped? idk why but yeah and its saddening :/