If my prepaid service runs from the 7th of the month to the 6th of the next month and I want to change to a different prepaid plan, which date do I need to change it on? The 7th or the 6th? I want my renewal date to stay the same so that my service continues to run from the 7th of the month to the 6th of the next month. I also don't want to be charged extra when switching from the old $45 plan (1GB) to the new $45 plan (2GB). I'm enrolled in autopay.