Bill Invoice is in not same as writen bill at sangeetha Mobiles

Location/place: Road No-3, Banjarhills, Hyderabad

Name of company/service: sangeetha Mobiles

I have bought a Cell phone bearing model ( NOKIA C6-01) on 11/11/2011 in the name “Kiran Kumar Kompella” from Sangeetha Mobiles Private limited ( Ameerpet Branch). On purchasing time they are given Written Bill.

I had Lost this Cell Phone on 30/07/2012.Value of the loss incurred was Rs 13858/-. Then i had registered a Police Complaint on 31/08/2012 in Banjara Hills police station.
So I tried to claim the mobile insurance, they asked me Bill Invoice.
After that I went to sangeetha Mobiles for Bill Invoice they gave me a Bill Invoice with some other name and also the invoice is not in correct date But the IMEI no is same as written Bill.

In written bill they mentioned my name only But Bill Invoice is not in my name what can I do for this

Details of Mobile.

IMEI NO- 358627043673787
Model- NOKIA C6-01
Cost- 13858/-
Bill Invoice- SI/AME/9521
Invoice Date-22/11/2011
Mobile Number of the lost phone-9440910524