Screen Flickering

I have an LG Xenon and found it an OK phone except for a few freezes. Well I've had it for a few monts, haven't abused it in any way except dropping it once or twice but not onto concrete, onto grass. A few weeks ago, without anything else significant happening to the phone, when I pressed the green (call) button while the phone was slided open the screen's brightness would go up and the color quality would go down and it was flickering rapidly. I found this odd but it didn't bother me much.

Anyway, today I pressed the button again to send a text to my friend, and as usual the screen "lit up" in its odd way with the flickering but this time it didn't stop when I pressed the button. I pressed it again and it got worse. After turning off / taking out battery and SIM card / turning back on and recharging / rebooting again, the screen is still extremely bad and quite unreadable. I also have some sort of "burn-in" like on a CRT monitor. My background image shows up as a shadow when on other pages such as the Dialing application.

Any help would be greatly appreciated.
Thanks in advance,

gdea73