Jodey

Leaving on a cruise next week and have found the drink package for a good price online. As my OBC from the travel agency won't show up on my account until onboard, I would have to pay with credit card before the cruise. Is there any way to switch it to pay with my OBC once onboard or am I going to have to wait and pay the higher price? We also have free gratuities and specialty dinner so would really like to use the OBC on the drinks.