damaged goods and bad attitude

I bought an LG Television on the 25Feb. 2015, I took the TV home sealed in a box they did no check if it was in a good condition , when I opened it at home I had a problem with the settings and I also realised that there were lines on the screen but I Thought it was also part of the setting,, so the next day I went to the shop to ask them to assist me with the settings, then I went back home only to find that these lines are still there when I took a closer look now I noticed that there is a crack on the screen. I took the TV back to the shop, They refused to take it back saying it was my fault. Sifiso( supervisor) was so rude to me , he made me stand there for about 30min unattended, He went out and came back with a shopping bag, He even refused to give me the managers number, I left the TV there at the shop