Thompson — Picture type issue in the newly purchased TV

Address:

H C 254 PHASE 1 ANNA NAGAR TRICHY 620026

I have purchased Thomson 42 inch TV and very soon after the purchase I find granes dots and black lines on the TV and while booting up I find scrambled lines. The TV is within the warranty period, However I have wrote multiple times to customer care and no proper response from the team.
I want the issue to be fixed asap. Since buying a new TV and finding multiple faults and definitely unfair.