I would Email the makers of the game directly maybe with a vid attached showing the pressure needed to remove the game from the defective case and a pic of the crack. I doubt they'd give a full refund but might at least give a voucher as a good will gesture, maybe, lol.
The game makers? SEGA? This is Sonic Unleashed, but I doubt they'll refund anything...still I just wanna see what they have to say for themselves, though maybe it's not their fault, Microsoft must've forced them to use this design at some point...and then discontinued it...also no point doing a video now as I removed the 4 tiny spiky things that were forcing pressure on the discs...