mobile ka tuch folder ablable please help me

Recently purchased Phicomm mobile through Amazon is not working and overheating. YouTube stopped working error message showing. Chennai service centres as per website are not accepting even it is in an under warranty failure. Need solution to fix this issue.

Ibeing a Sr. Citizen have delivered my defective mobile model no E 653 long back to your Chennai Service Centre after speaking to Mr. Saravanan ( Head of centre)
But due to high repair cost it is not economical for me to go for repairs. So I requested him to send my mobile back which he didn't send nor he is responding me against my lots of email reminders. Pl.take action soon & return my mobile.

Please coat price of display replacement and availability thank you