Green Mobiles, Bangalore — poor quality handset

I have purchased redmi 4 mobile 4gb - 64gb. But the quality is not upto mark. Had complained on 15.09.2017 for the handset is not upto mark. It gets heated. Hardware issues. It hangs. Camera is blurred. Engineer have checked and reported the same issue. I have the copy of engineer's report. When i contacted to amazon, the call get disconnected. Now no response available on the site. Now what to do?