Airtel — unlock of sim

I lost my mobile recently & immediately blocked my airtel sim. I bought a duplicate sim 5 days back from nearest airtel store. My sim is not activated till now. I went to the nearest airtel store & i was told to call the customer care again & unblock my sim. For the past 2 days i have been trying to reach the customer care but i couldn't reach, reason being heavy rains in chennai (Inspite of the fact, there was no rains at all). The response is poor even at the airtel store and at the customer care service department. There should be an instant contact number to the customer care executive in emergency cases. I am unable to unblock my sim till now. Please do the needful.