Airtel Prepaid — Mobile no. diaconnection

Address:

Hyderabad, Andhra Pradesh

Sir/Madam
My name is Suresh Kanaparthy. I am having Airtel Mobile connection since 9 year(Approx.) in Andhra Pradesh State.
My Airte Mobile No. is [protected] .I have started this no. as postpaid for 4 years and then converted it to prepaid lifetime plan. Resently since last few months this Mobile No.not in use . From last few days my mobile no.-[protected] is not working(Neither I can make call nor receive).
I asked Airtel's Customer Care, Airtel's Customer Care Relationship Center- Ameerpet Airtel Headoffice, Nodal Officer . But answer given to me by above all Responsiable Parsons (for Airtel Customer Care) mismatches with each other's answer.
I talked with Airtel'sCustomer Care Relation Ship Center Head on dated 10/09/2010, he told me that you have lost your Mobile No.-[protected] and it will come in market on date 21/07/2010.
So, now I don't know what to do? Why Airtel's employee can't give a proper and unity answer that because of which reason My Mobile No.-[protected] is deactivated?
Then I Talked to the Nodal Officer on dated 10/09/2010, then informed me your Mobile No.- [protected] is in Open Market, then i asked to reactivate it, they informed we will forwarrd a request,after one weak follow up on 17/09/2010 I came to know that My number was taken by other person.

How it is possible in very-very sort time?

I need my no. as I used it for almost 9 years.

Please help me..