Phone problems

You want to know what really grinds my gears? Ok well even if you don't want too, I'm going to tell you anyway.. I have Sprint service. . I can't even tell you how many times my phone just randomly freezes, and at teh worst times! I'll be having a serious phone call that is extremely important that is time realted, and then my phone will just randomly freeze up for fifteen minutes and then work just fine again. Not only do I get ticked off, but the people I was talking to become pissed off as well because they think that I just hung up on them! Is there anything I can do to prevent my phone from randomly freezing?