Damage Goods & Bad customer care

I bought a Sansui 48" on the 25th of November 2018 and I didn't open it for two weeks as I wanted a TV stand that could fit. On the 9th of December 2018 when I open a TV half of the screen is black. I reported online on the day of incident and called them the following day they told me to come with it in the store. When I get there they told me it probably my fault and they can't pay it off. The manager decided to undermine me by telling me that maybe I didn't know how to handle a tv because his guys know how to. They told me warranty doesn't work on this I have to fix it my