Since it is less than a year old call AppleCare: 800-SOS-APPL (in the US).
Have your Mac's serial number ready: http://support.apple.com/kb/HT1349
After you wait on hold for a very long time they ask you some frustratingly basic questions like is it charged and did you spill water on it etc., they will talk you through some basic troubleshooting such as an SMC reset. In the end they will offer to schedule an appointment at a Genius Bar where they will fix whatever is wrong. It won't cost you anything (unless you spilled water on it etc).
You can do all this yourself:
Resetting the SMC on portables with a battery you should not remove on your own
- Shut down the computer.
- Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
- On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
- Release all the keys and the power button at the same time.
- Press the power button to turn on the computer.
Genius Bar Reservations:
You can test the hardware yourself also, if it reports something wrong tell them what it is.
Using Apple Hardware Test: