From CAG (Again)
The locale you're setting is your system's locale, not the account's.
Props to dudeman06 in another thread:
"I got injustice to work again!
1. Set your locale to Austria.
2. Sign in to any account then immediately sign out. The home screen should have a tile with superman on it now under the FIFA 14 tile. Click it.
3. You should see Injustice as 30% off. Sign in to your Morocco account now.
4. Click the Injustice sale tab and you won't get the error and it will show up as free instead of the sale price.
Enjoy your game! First time I've contributed so I hope it works just like it did for me. "
I just added it to my download list now.