Airtel — Airtel showing No Service

Hi,

I'm using an Airtel sim for last 4 years, I got my 4G sim in Chennai, India. Two years back I came to Australia and brought my sim with me as I need it for otp and other transactions. For the last weeks I'm getting No Service in my Airtel sim and due to current covid situation, I'm stuck here. When I checked with Airtel customer care, they are asking me to bring the sim with an Aadhar card which is impossible. I cannot leave my job here and come to India for this issue. I also emailed Airtel care explaining my issue but no response yet. Please advise how can I fix this issue. I badly my sim working with the same number.

Ps: my sim is currently in India, i sent it via my friend who left to India.