Every time I try to turn my iPhone 4s off, it turns back on by itself?

Right now I've been trying to turn off my iPhone 4s but every time I try it comes back on by itself. Not sure what's wrong with it. And has anyone else had this problem?

Details:
-iPhone 4s (16gb)
-Updated
-Purchased in November 2011

And recently I had another problem. My sound wouldn't play out loud but could only play if I plugged earphones in it and sometimes when I listened to music it would stop. But the problem was fixed by itself.

Normal glitch for the iphone 4s. Inform Apple about the complication and they should help you further