Airtel — airtel number deactivated

Hi,
I am outside of india, i have the sim card with me, it was working fine, but just after 90 days, it stopped working. It looks like the sim card has been deactivated. I want the sim reactivated.
Could you please activate the sim? Also please let me know how i can continue to keep same number for long time even if i dont use, i will use only to receive sms. If there is any monthly recharge is required, please suggest. My no. Is [protected] (Kolkata)