It's important to keep in mind that a newly created trial account that has been upgraded receives 40 days of free game time. Accordingly, the account is not charged a subscription fee until that game time has expired. Your brother is welcome to purchase a prepaid game card from a local retailer or a game time code from the Blizzard Store (http://us.blizzard.com/store/details.xml?id=110000004) if he would like to add time to his account immediately so that you may claim the mount sooner. Once 60 days' worth of game time has been purchased, you will be able to claim your rewards.