Airtel — number disconnected without prior information

Address:

Prakasam, Andhra Pradesh

Hi,
i am using my airtel mobile number for 4 years,at first it was a postpaid no later i have changed to prepaid ,but i didn't get the deposited amount also,but recently they have disconnected my mobile number without prior information,even it was recharged with a life time recharge,
when i was in karnataka for a trip ,i didnt used it for 20days,for that sake they have disconnected my number.i need my number,it is a very important for me,please help to get it,what is the process to get the same number.i asked the airtel district outlets, they said that the no is made a free number and u cannot get the number.

thanking you,
kiran kumar
airtel no :[protected].
my alt no:[protected].