Both the volume buttons and mute switch on my iPhone 5 don't work?

I just got my upgrade from AT&T and noticed the volume buttons and mute switch don't work for some reason. Is there anything I can do to fix it or should I just take it back to AT&T? Or will they just send me to the apple store to get a replacement?

If you are not a technician of cell phones, take it back to AT&T.

They will send you to apple to get a brand new iPhone 5 from them.