Mitashi Edutainment Private Limited - Regarding request for warranty within warranty period

Ref: Invoice No.- MP/****/SA/***** dated- **/**/**** of Great Eastern Retail Pvt Ltd. West Midnapore.
Model – MiDE***v** HS
Model No. – GR**************/SR No.- *************
Complaint No. – **************/ Dated: **/**/****
Extended warranty No.- MEPW************

I had purchased the above-mentioned Smart TV from the Great Eastern Retail Pvt, Ltd. Keranitola, Judge court Road, Midnapore – ******, West Bengal on *th July **** vide above-mentioned tax invoice.
On **th July **** evening, while I was watching a programme on this television a grilled line had appeared on the television screen. For that, I made a complaint to the customer care vide above mentioned complain Number. Initially, I have observed a black spot on the right bottom corner of above Tv monitor. The grilled lines on monitor spreading throughout the monitor, day by day and ultimately after *-* days on *rd August **** there was no picture on the monitor.
The technician had come and visited my place on *th Aug.****. After inspection, the technician denied the warranty and claim a chargeable repair. Saying that it was not happening automatically. It happened only because of hitting from outside of the screen. But it was completely wrong explanation/observation if it was due to hitting from outside then obviously there would be a sign of hitting on the outer surface of the screen but there is no such sign. I assure you that it happened automatically and it is a very genuine case of the defective product.
I have reported the above matter to them several times through email but despite all my pleadings they have not made good the defect in the goods neither given any assurance of that, which is indeed regrettable and highly unprofessional.
It is requested to you to look into the matter and help me.