Fraud on account of changing the IMEI no

Location/place: Bangalore

Name of company/service: HTC

Here is the detail of the incident happened to me . On 25th October 2012 i lost my mobile while traveling in the bus .Same day I logged an FIR for the same in the local police station (MICO LAYOUT POLICE STATION , Bangalore). Then on 28th October I received a call on the same mobile no (as i have got same no issued by the help of the FIR ) and that person returned my mobile .So i went to police station and cancelled by FIR. Then on 6th Dec i gave my mobile to the Fine Fone Service Centre in Jayanagar to get it repaired as it was under warranty . They returned by mobile on 12th Dec . I continued using the mobile till on 5th Jan i received a phone call from the police station . I went there they asked where is your mobile i gave it to them . Then they checked the IMEI no in the phone and behind the battery on the sticker both where same but different from the IMEI on my bill . Then they told me that this is not my mobile . They also told that my previous IMEI no is switched off from 7th Dec . So now I asked written prove from HTC stating that they have changed my IMEI no . After calling their support center several times they told me to collect the details of the service from Fine Phone Solution . And what they did was really not expected they gave me on the same Delivery Challan just writing using pen my previous and current IMEI no.