Sorry, prepaid does not work that way. There are no extensions. You prepay for service and when that service expires, your service stops until you pay for more. There is no penalty to pay late. You can wait 2 weeks to pay, you just won't have service until you purchase more service. If you do not have enough to pay for a 30 day plan, you could switch to the $0.25/minute plan and put the minimum $10 on your account. At least you will have service. When you have enough for your 30 day plan, then switch back.
Award for Community Excellence 2019 Achiever* *The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.