Samsung — Non working of LED TV Screen in just four years of purchase

Since some days my Samsung N4310 series LED tv's screen is not reflecting and for the same I have lodged a repair request. Engineer, who was visited today and informed us after seeing the TV parts that the picture tube is gone. it needs to be replaced and cost around Rs. 9500/-. I am surprised by hearing this. In just 4years the TV of Samsung company, a brand image got damaged. It is very unfortunate how this type of things happens. I have purchased the TV by spending at about Rs. 20, 000/- and now the engineer is saying to pay Rs. 9500/- [approx.], if we want repair. Please lodge a complaint regarding the early damage of the TV screen and take necessary steps so that the same can be repaired / replaced without any heavy cost.