Apple India — iphone 7 - audio problems & phone getting heated up

This is to bring to the notice of the forum that, i have not been provided enough support from apple on the iphone 7 which comes across having "audio problems" & "gets heated up when in use even for a short while".
Below is the brief description of the phone :
Apple iphone 7 128gb rose gold
Sl. No. [protected]
Date of purchase : 26-nov-2016.
When reached out to the apple online support, i was suggested couple of workarounds with the device reset which seem to work for while but did not sustain. Later, i was asked to carry it to the authorized service center and i was told strangely that there was no fix for this issue.
And there have been more than 50 complaints in the last few weeks and apple denied any support other than suggesting buying another phone with the replacement cost.
Though the phone is beyond its warranty, this indicates the phone to have a serious safety threat and even then apple is not acknowledging to recall this product.
Please help provide advice & support in terms of reporting this issue to apple and get justice on this.