How do I go about adding data to my plan? I thought I got a popup notice that data was running out and it was $10 to add 1GB to my plan, but I can't find this anywhere. I have the 3GB for 30 days plan. Can I buy another 3 for 30 plan when mine is about to expire and go from there? would i need to cancel the existing one first? I originally thought if i went over i would be charged 15 per GB, but in the terms and conditions it says i won't have access to data once the plan expires.