Bad customer service, rude staff

I have bought an Hisense TV,yes the person who assisted me,switched it on before we left the store,but while he was putting it inside the box 📦 I think that's when he caused damage to the screen...when it was time for me to switch it on...I saw the scratch, which you won't see when the TV is off.....the rude store manager and his customer services person they refuse to assist with exchanging of TV,they say I am the one who caused damage to the TV....while it was they are fault....