discrepancy in mobile repair

Location/place: Kolkata

Name of company/service: Nokia

I possess a nokia X6 handset and I found a occasional display flickering problem and deposited the same for repair to nokia care in saltlake sector 5 kolkata on 18th december 2012.While depositing they told the display needed to be changed at a cost of Rs 2500 and I agreed the same. After few deays they told me that the device cannot be repaired and when I went to collect the handset I found that the phone is totally in a unworking condition whereas I submitted the same in a working condition with a display flickering problem. I denied to accept the handset and insisted to return me the handset in same working condition as I submitted. They told me to give some time and then again after two days they called me and told that the ic needs to be changed at a cost of Rs 1800 and I regected to their offer and insisted to return me the handset in same condition as I submiited or to issue an warranty of minimumsix months on repair. They denied to do so and told that the handset can be returned in working condition if I agree to repair for Rs1800. They had harassed me in all ways and it shows clearly that they had misused my phone parts. Kindly look into the matter and give me justice.
Thanks and Regard Sudipta biswas -9830040604