@pompeynick667 seems like you're not the only one, see pages 84 onwards, https://community.giffgaff.com/t5/Announcements/Did-someone-say-quot-more-data-on-the-10-12-and-15-goodybags/td-p/23649951/page/84
I'm assuming it's a mistake and that GG will sort it, but, might be best to flag it with an agent anyway.
