iMessage Activation not working iPhone

Hello,

 

I have iPhone 4 using since last 1.6 years now.

 

One fine day iMessage just stopped working.

 

After that I've been trying to avctivate and it never works it says "Waiting Activation"

 

Steps Taken:

 

Tried doing Phone reset.Tried doing Network resetTried doing Removed everything and installed firmware again and before restoration of phone tried doing the activation but no luck.Now I don't want to try the new userid as that is my everything and is associated with my email which all my friends circle, family, business contacts have.I have spent a lot of money on this (The automatic SMS is sent for activation which costs 5 Rs (INR) of each message, and it keeps sending this SMS after a period of time, until I switch off the iMessage)

 

 

Please Help.