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Okay so my touch screen won't function if the device is not in my hand (weird right).
And also, when playing music, my lock screen gets stuck on a certain album art, and the little buttons (like next and pause) won't work. (when your headphones are plugged in you have shortcuts on your lockscreen)
and I noticed it's very difficult for me to answer a phone call (when you have to swipe down like the lock screen) it takes a few tries.

Re: Should I get a new one?
 

as for the touchscreen not functioning when its not in your hand, did you try and run the calibrate screen setting?

Re: Should I get a new one?
 

Before going through a full return, try resetting the device to factory defaults, and run the screen calibration wizard. I had to do that when I got mine as the screen registered my finger-touch a little higher than actual.