I was randomly browsing Ultimate GCs at Coles and decided to scan Ultimate Student card version. To my surprise, it gave 15% discount. I bought $50 cards but the discount also worked on $30 card.
It may be linked with following deal but this card type is not mentioned in catalogue.
I thought this deserved a deal in its own. It's pretty handsome discount for people who recently pre-ordered Xbox via EB games.
Full list of stores that accept this card is available via link below.