My Sony Ericsson K660i got wet, and now the screen won't work?

My phone was chewed by my 9 month old and dribble got through the handset and damaged the phone. When you switch the phone on you get the Sony start up screen, then it goes black. I can hear the phone is working when I press buttons, but the screen remains black. I did send the phone back as it is under warranty but as the damage was due to moisture they are unable or unwilling to fix it.

Can anyone help, would a replacement screen be an option in this case. Any advice would be much appreciated. Thanks