Airtel — Unable to get my Relieving Letter // Experience Letter

Dear team, I was worked with Bharti during year 2006 to 2007 .
I need my Experience certificate/ Relieving letter from bharti but nobody responding, from last few years i was tried for letter from local HR office but still no response.
I got information about site for airtel ex employee."www.airtelambassadors.in " but i m not able to register on as my Emp. ID is not found in database.
So kindly help me to sort out the issue. i joied in Bharti Comtel and later Bharti Comtel changed to Bharti Airel Services Ltd.
Name :- Deepak Pandey
Org. :- BHARTI Airtel Services LTD.
EMP.NO:- 24786
Contact :[protected]