I purchased a Nokia Lumia 720 on 21st December 2013 from the Nokia Priority Dealer addressed as DN 1 ,Salt Lake ,Sector V,Kolkata -700091 .

From the day I purchased , people started complaining that my voice is not audible. The level of my voice was uneven . They could hear some words and they could not hear some words. Meanwhile I was also facing some minute noise in the background while talking to someone.
I went to the Nokia care(address mentioned below) they replaced the microphone and handed over to me in a week(31st Dec,2013). But I was still facing the same problem. I again went to the Nokia care and addressed them my problem. In another 3-4 days(date : 7th Jan 2014) they returned back my mobile saying that they have cleaned the microphone and guaranteed that I wont be facing this problem.
But actually nothing has happened . People still complain the same while talking to them.
Spending around Rs 18,700.00 and not even getting a normal phone facility is really frustrating. Its been 3 weeks and I havent used the phone for 15 days also.
Please help me with my problem . I am really frustrated with the Nokia Care center I am talking about. Though their behaviour was not bad at all.

I would claim for a replacement or money back. I dont trust the Nokia Care Service now .

I have also sent an email to social@nokia.com with all the details.

Thanks