Xperia Z2 :: Dead Display And Touch Screen On Phone

I'm Sony user since 4 years ago as I started with Sony Xperia miny pro, Xperia S, Xperia Z1, then Xperia Z2.

Now I own the black model of the xperia Z2 since 2 days I decided to try the waterproof ability and take a photo under the water. I took the phone with me under the water it's not more than 30 meter and not more than 6 min .a few hours later, I found out that some of the water got in because I can see some condensation on the camera lenses both front and back.

Another few hours later I found out that the screen starts to flicker then the screen dies. All other functionality such as the sound still works because I can hear the tone if someone call me or receive a sms but the display and touch is dead.