Sony India — sony team not responding to any of mail regarding my mobile issue

Address:

Pune, Maharashtra

as i have submitted my complains before to this page, the same issues i am still facing. my mobile phone is still in aaradhya Sony service center and its already two and half months its in service center. no one is responding to my mail, no one is bother to resolve this issue. in short they have replaced all the parts of my mobile but still no solution. after that they replaced motherboard two times but same, no solution. then they gave me two times new replacement of mobile but both replaced mobile also was not working properly. so i have submitted on the same day. and i have asked for cash back. but they have refused it. so i asked for commitment from them, that is "i will accept i[censored] give me brand new mobile with seal pack box and after that if i will get any problem like before then you will give me cash back." but till today i haven't received any revert from Sony centre. when i have submitted my mobile on 30/03/2015 till that day to today i everyday mail to Sony care team but till today i have not get a single revert from them. please help me out.