Water damage! Did I make it worse!?

Friday night at a club I set my phone down on a table now knowing it was wet. There was only a little water but apparenty that was enough to wreck havoc on my phone. I think it was probably in the water for about 10-15 minutes. The water was as if someone has just wiped the table down so I shocked this was enough to damage my phone. Anyways when I picked it up i noticed it was a little wet, wiped it off, and when I went to make a call the screen was black. I panicked and took the battery out. I put it in rice for a day, took it out this morning and it worked PERFECT! Nothing was messed up, I was happy...for about an hour, and then when hooking it up to my charger the screen went fuzzy with red and black dots and then went black again. The phone is still working but once again the screen is not Maybe i should leave it in the rice longer? Do you think I may've caused permenant damage by turning it on before it was completely dry? Do I have any hope?!!