Virgin Mobile answered your question in the FAQs tab:
If I'm currently on a Virgin Mobile BroadBand2Go $10/$20/$50 plan, will I be able to keep my plan?
Yes. If you bought a $10/$20/$50 plan before 7/4/12, you will be able to keep your plan at this time, unless you switch to another plan or until the plan is discontinued. However, if you are on one of these plans, you will not be able to enjoy 4G speeds, even if you have purchased a 3G/4G device.
answered 2 years, 8 months ago