Well, you can try blowing the game chip part of the game chip (the bottom of the back side of the chip, not sure what that is called) and blow on that. Then blow in the game chip slot. Then try playing it again.
As a last resort try restarting your game and see if it works. If that doesn't work, just take it back and get a refund. You got it yesterday, so I'm sure the store will have some sort of warranty.
Have you been to this game store before to get other Pokemon games? Or games? Or anything at all, really? (xD) Because if it's your first-time there, maybe you shouldn't come back there. It might sell fake games.
Hope I helped. :)