Good news for all of those who have been unable to restore their Summoner Wars iOS In-App Purchases since upgrading to iOS7, the issue has reportedly been fixed. Here's where I heard it:
He in turn heard it from Gary Weis of Playdek:
Give it a try if your copy hasn't been working, hopefully it's a universal fix.
Also, shout-out to users Mundungu and Glenn3e for advancing to the Championships in the Official Winter iOS Tourney!