HTC ONE V network signal problems (and a very bad phone)

Hi,
I have a htc one V phone . I am facing network issues on this device . When the signal of my carrier (Airtel in india) is weak the phone is unable to receive any connection and there is no network in my phone wheras when i insert the same sim to any other phone there is network even in low network areas. I know this is a problem with my device as all my friends with the same carrier receive strong signals on their cells in the same area ,where my phone receives none , also I tried changing my carrier sim but sim but same problem persists .Please suggest a solution .
Phone - HTC ONE V , bought in may 2012 (the same time it was launched here)
carrier- AIRTEL
location -INDIA