至于楼主的plan 确实如你所说的收费的 网站上也说的很清楚: Double your data
Our 3G broadband Everyday and Pro plans come with bundle insurance. If you go over your included data allowance, we'll automatically double your data for just $10 more. You don't need to do a thing, we'll double you data automatically if you need it.
If you hit your limit again, extra data costs 50c per MB.