Nokia N8
Network not receiving

I am using nokia n8 from 29.01.2012. some time was network not received on my mobile . still today my mobile is offline mode, so i am try to general mode in my mobile but this is not indicate my sim card on my mobile. so i am very very suffered today. because i was purchased this mobile rs. 23800/- in gujarat. pls help me.

Regards,

Thaveethu raja (David)