iPhone 5s dropped in water & now he gives me "no service

Hi Guys..

so my iPhone dropped in water , i tried to dry it and its worked for me ... then after 2 weeks maybe he gives me "no service " i don't know why i tried to replace the sim card and put new one but unfortunately didn't worked,so i went to store and they did says to me maybe its from the battery they replaced and like last time didn't work still gives me "no service" .. i tried allot of things to fix it but it doesn't work

so please give me answer if you know

thanks!!