Just started a prepaid account this month on the $70 a month plan.
Already have only 9GB of data remaining. Based on my usage it's clear that I was only credited with 15GB of data instead of the 30GB as advertised on Verizon's website:
https://www.verizon.com/prepaid#jetpacks

Confirmed with the representative I spoke with yesterday that I would receive all of the data under the double the data plan. Unable to connect with a live representative when calling into customer service.