Airtel
Prepaid mobile number deactivated

I was using an airtel prepaid number, Kerala (9995555090) since september i didn't use this number for 2 months and now it is deactivated. I didn't get any intimation regarding this. When i check with the subscriber they said this no is issued to another person, how can they do this with out my permission. Kindly help me to regain this number.

Thanks

Ginju P R