K790i
Hanging Keypad

I m a Bangalorean purchased phone in september, it gets hanged very often, few keys dont work esp Joystick .i have serviced it twice- first time in Malleshwaram-Numeric Communications and for second time Sony Ericsson Service center Rajkumar road, Rajajinagar I m Facing the Same problem again. Is There any other Option I can go for???