Nokia N8 — very frequent problems

Address:

Bangalore, Karnataka

I bought NOKIA N8 about 5 and a half months back and have been facing too many problems with it, sometimes messages wont be sent, sometimes the phone restarts automatically,etc etc...
within a span of jus 5months, I've given my handset to NOKIA Care 6 times and everytime they flash the software and give, initially there wont be ant problem but after a few days again some or the other problem starts... I WANTED TO KNOW IF I CAN CLAIM FOR HANDSET REPLACEMENT FROM NOKIA BECAUSE OF VERY FREQUENT PROBLEMS.
MY HANDSET IMEI NO IS : [protected].