To get ? and ! you must first capture all of the A-Z unown.
THEN, If my memory serves me right, you gotta talk to the guys at the research center next to the entrance of the ruins.
THEN go back to the ruins, but don't go down the ladder, ! and ? are in the room when you first enter the ruins.
(An easy way to tell if you can capture them yet is if there is a golden panel at the back of that room that was previously the same color as the walls. From that point on ! and ? are forever in the room.)