false impressions via advertising SONY EXPERIA Z3

So I was happy to get the new waterproof sony experia Z3 on 20 dec 2014. Took a couple of pics under water and wow! Loved this phone. But on 25 january 2015 the screen just went blank while I was in the office. Got very very hot. Could hear msgs come through but no screen. So I took it back to vodacom. They send it away and the verdict?? Water damage???? Really??? So luckely I have voda insurance. Have been with vodacom for bout 11 years and never ever have I had to put a claim in..so after having my phone for just 36 days I now have to pay in nearly R2000???? Where do they think I have to get that? And for a phone ADVERTISED as water proof? I took pics under water in beginning of jan??? So what does vodacom answer me? Take it up with sony...I am lost..don't even know WHERE to start to contact these people..please can you help me?? Job Number ***0