Glitch in Blackjack

2 or 3 times a week my Blackjack locks up, clock stops and nothing responds to keypad or anything. After several attempts to turn it off, it will turn off and when I turn it back on the clock has reset and everything works again until the next time. It seems the frequency of this glitch is increasing over time.

I had to take my phone back to the service provider once to have them do a hard reset on it, loosing everything, when turning it off did not help. I have only had the phone for 5 months. Did I get a lemon? Is this a common problem?