Airtel — my 1 year old airtel number is deactivated

Address:

Tirunelveli, Tamil Nadu, 627811

Dear airtel customer care officer,
I have used a airtel prepaid sim since 2016. Few months later, my sim was deactivated. When i contact the customer, they said that your sim was deactivated due to not in use for a month. And they also told that my sim will also sold to someone. When i go to the nearby airtel showroom and ask about my sim card, they told that your sim with old number could not be activated. So please help me to retrieve my sim card with my old mobile number. My deactivated airtel mobile number is [protected]. Please retrive my sim.