I got one ebay after my enrollment wasn't filled got 6 emails to update billing been fine last 20 coins?. paid extra$20 ! So done with us mint!!
You actually have to go into your annual enrollments and change it there. It was happening to me as well and it was correct in the area where they store your CC information but not in the annual enrollment page. You have to delete the old and add the new. Don't ask me why it doesn't automatically do that. I missed out on the 2020 mint set because of that.