Airtel — want to Discontinue mobile no [protected]

Address:

Mumbai Suburban, Maharashtra

I want to discontinue [protected], i have used for more than 2years.
My no is [protected], which was CUG no from company M&M, Mumbai. Since for very long I left mumbai & stopped using mobile since Feb2010. I request you to discontinue my mobile no. I am redy to pay any pending bills.
In this regards I have contacted your help mail id may times [protected]@airtel.in as well as telephone no. but no action initiated. it has been told that i need to come to mumbai & book request for same in hard copy. which is impossible.
Today i have received mail from airtel.[protected]@gmail.com, some collection agency.
RMS SUEPRSONS SERVICES
AUTHORIZED VENDOR
AIRTEL COLLECTION DUES.

Please help in resolving matter urgently.

Regards,
Deokar Prashant