Airtel — Sim card became dead

My Nam is srikrishnavaraprasad jasti and I am a pensioner. My airtel prepaid SIM card became dead all of a sudden and no SMS or calls. I have been using sim card for the last 5 years. I am presently in USA and require my mobile number is required to generate life certificate apart from other services. I request necessary action be taken immediately to resolve the issue and activate my SIM card .Alternatively I request a sim card replacement be provided.