broken tv

I bought i tv from lewis store two years ago and took it in for repairs a two months ago just to look at the sound and get it fixed the store had the tv for a month and two weeks after the month and two weeks when the brought the tv back it didnt wanted to switch on but at the time i took it in it was working perfectly the only problem was the sound a week ago they told me theres nothing they can do cause insurance and factory warranty is no longer in process but still had the tv but when the tv came back to me it didnt wanted to switch on or make anything now im sitting with a tv that not working and the store say theres nothing they can do but im sitting with a blank tv thats 20000rand worth can you please assist me