excuses to repair TV

I have a Samsung 7 series 55 inch tv which developed a random dot on the screen about the size of a 50c coin. This has slowly grown to about the size of a tennis ball. The service guys from SSS came out on Friday and said its physical damage to the TV and someone knocked it from underneath. Firstly, the gap between the TV stand and the TV is 15 centimeters and impossible to knock. there are no marks bumps or any scratches proving that there was any physical damage. not even a crack on the screen. The TV is 9 months old and Samsung are looking for excuses not to honor their warranty.