help needed grey shadows on screen

[mkc11]

I have a LG32lx2r which has just developed a fault on the screen .Grey lines have appeared in the middle and top left sections of the screen they are not noticable when against bright backgrounds ie white yellow light blue , but are very noticable against blue and worst of all green backgrounds especially fast moving football. I have fiddled around with the settings and the effect gets worse the more the contrast is reduced.The lines started out quite thin but have gradually spread out .Any ideas please. the tv is 20 months old and out of warranty