Problem with my motorola pebble?

this is a problem that i have experienced before but basically my phone has switched itself off and won't switch back on. the problem isnt that it needs the battery charged as it has had the charger in all morning. usually when its charging it kind of turns on so you can see the screen and the time and everything but this has not been happening today. when the phone has done this in the past it has generally started working again normally after a few hours however, i need to check my messages urgently. i have tried taking the sim out and putting it back in but this does not seem to help at all. anyone know what the problem is? or what i can do about it? xx