My dsi broke.how can i fix it?

my little sister was banging it on my grandmas wooden table about 100 times.and when it was time to go i grabbed my dsi and turned it on in the car cuz i was bored so when i turned it on everything was perfectly fine except i could'nt see any thing it turns into all sorts of colors but its only the bottom screen.oh and also my mic is broke i tried the mic test and it was not working.so do you guys no how i could fix it or do i have to bring it to a repair shop?