I bought a brand new TV from CELL DOME, but it stopped working

I bought a brand new TV from CELL DOME, but it stopped working. Luckily, it's still under warranty. I have all the documents, including the proof of purchase, but I lost the original box. Now, the warranty people are refusing to replace it because I don't have the box. I'm stuck! Has anyone else ever faced this problem? Do you have any ideas on how I can get my TV replaced or fixed? Share your thoughts and help me out!"