BlackBerry Help!!!!!!!!!?

[2.14.10<3]

Okay i have had my blackberry for under 30days. I downloaded music from the music store and use the internet. Now all of the sudden my screen freezes and its shuts off and restarts. Also after 5 minutes on the phone my screen go black and wont work at all. Unless the person i am on the phone with hags up. Should i go to the sprint store, or just let it go