Oliva LCD tv has developed streaks in the screen.

Question

I bought an Olivia 327-S12 LCD tv a couple of years ago and it has just developed streaks on the screen and I can't seem to get rid of them. The steaks actually look like dark stains, as if someone has spilled some coke on the screen. The rest of the screen looks great and I can still see the picture through that darkened area but obviously it's a distraction when watching tv. I've tried adjusting picture settings to no avail. any and all help is appreciated.Thanks.