Airtel — mobile network not available due to sim issue

Hi,

My airtel number suddenly stopped working and is showing mobile network not available. I am not able to make or receive calls, messages though other neighbouring airtel sims are working. I have recently recharged unlimited talktime as well. I tried raising complaint from my mail but no response as my mail is not registered with the number. To register my mail, i need to verify the otp. Since i dont receive any messages, i am unable to do. Kindly request help from airtel.