Is the cd a conventional disc with no paper label or debris on it? Do you hear the motor running, trying to eject the disc? Is the unit in cd mode (will it play the disc), or has it reverted to tuner?
Just curious, is the unit standard am/fm/cd, or the navigation unit? The conventional is Mitsubishi Electric, the navigation radio is Panasonic.
If the disc was clean and not warped you shoud be able to have the repair done under warranty, as far as I know. Hopefully the dealer would swap with a new unit, but if like the old days, it gets sent to an authorized repair center.