Greetings ,
Thank you for contacting Warner Brothers Technical Support.
We are sorry to hear you are having some problems with your Injustice: Gods Among Us on Android.
Most likely you rated the game from outside of the game and/or signed up for your WBID account outside of the game. That will not grant you the content.
There will soon be a fix for the game not saving to the cloud. Once that fix is available, I would suggest backing up to the cloud, deleting the game and reinstalling it.
You should at some point soon after that, be asked to review the game and obtain your content.
We are sorry for any inconvenience this may cause for you.
Thank you,
Michael.D
WB Games Support