Problem please help - Phone acting up

[cmantis]

So I have been away from the scene for a little bit between work and school. My TP2 with android is now giving me problems. Very often when I make a call I can't hear anything until I try try again. Now it doesn't want to turn the screen on. I have to slide it open closed repeatedly and once in a blue moon when I press the top button the screen will come on. Also when I turn it off often it won't start back up. I have to remove and replace the battery repeatedly until eventually it will or I have to plug it in.

Is there any way to fix this or is there a newer build I can upgrade to? (how do I check what build I am currently using?).