Dell India — no realistic help received for defective product.

I bought dell inspiron 5577 laptop from amazon on 6/4/18 and received it on 11/4/18 (On installments, product price rs. 77, 895.00). I started noticing problems in the laptop since the very first day, like, sound distortion, google chrome freeze, groove music freeze, films & tv freeze and ultimately overall windows freeze. Dell premium support was in contact regularly and they tried everything but problems didn't go away. They even asked me to reinstall the windows and download all windows updates, which i did, but still problem of freeze kept happening.in mid-may, dell requested me to visit a service center and deposit my laptop there for fixing. I did so and got my laptop back, without seeing any major difference in the performance. The problem of windows freeze is happening again every minute or two. Sometimes it freezes for a 2-3 seconds and sometimes for 30 seconds.
After i told this to dell (Problems happening again even after service center fixed it), they asked me for evidence of sound distortion problem. I sent them the recordings and they asked me to send in another format because they were not able to play the files. I did again and dell has not replied so far.

When i told this to amazon on 26/4/18, they told me that the last date of return/replacement was 22nd. I requested them to do something and they asked me to obtain "service denial letter" from dell in order to get return/replacement request accepted. Dell bluntly rejected my request of that letter saying that they were not denying me service.

Dell has failed terribly to solve any of the issues that i have been facing. Neither did they solve any of the issues, nor did they help me in getting this defective laptop returned/replaced. That letter from dell would help me in saving my money. I am unable to use this defective laptop. I have been sitting helpless for last 40 days.