My DS lite mic is broked

I dont know how and i dont know why but its just not working..

I finally got myself the phantom hour glass and at the start you have to shout at this woman who is locked in some door and im shoutin my head off at the DS and nothing is happening..

So then i try brain training because you have to talk into the mic in some activities on that.. and what do you know nothing working...

I dont think ive had the DS for a year so maybe i could send it either Gameplay the place where i baught the DS or maybe Nintendo?? because its not been dropped or well basically hardly ever been played...

Has anyone else had this problem?