Which model do you have here? Can you try a Picture Test to see if the issue persists?
Head to > Menu > Support > Self Diagnosis > Picture Test. How does the image appear here?
If still under warrenty take it back. That is not a software issue I am affraid. Hardware fail or something dropped on the top, my pal had a new Sammy TV within 2 weeks one of his children hit the top with a heavy toy and the TV was ruined.
I have a dog!!!