Sony Xperia Z2 \Water damage"No Warranty??"""

I have a Sony Xperia Z2 on contract via Vodacom. The touch display was giving me problems so is sent it in for repairs. The answer i got was that the water indicator was activated. The phone has no exterior damage. I was then told that i would need to pay for the repairs as water damage is not covered under warranty. The phone is marketed as waterproof and through normal usage it now has damage. This is false advertising. Apart from recieving the runaround regarding the repairs i was told that this is a common issue and that the manufacturer can not be held liable??? This will thus be my 1st and last sony product that I purchase. The repair costs amount to half the phones value, and i can purchase a decent samsung product for the same amount and will be doing this instead of fixing a product that could at any stage stop working as I have experienced with the \Waterproof"Xperia Z2. """