Waterproof not so waterproof

I own a Sony Xperia Z which states that as long as the charger slot and the earphone slot is closed the handset it waterproof but as i was taking pictures at the beach on the 1st with friends a guy made a big splash next to us and covered us with water which is now the camera of the phone stopped working the -3 hours later the phone it self stopped working and i had to put a claim on my insurance for this which i believe that Sony is the one that should be responsible for the damage as they state that the handset should be water resistant i'm not happy at all with this Phozisa