Sony Experia Z3

I took out a contract with Vodacom Beacon Bay East London and got the Sony Experia Z3 waterproof phone, witch is a brilliant phone. 2 months down the line I got wet in a rain storm and tried to keep the phone dry as possible in my jacket after 15 min of being rain wet the phone started giving problems, first it started to vibrate and then only half the screen came on, this was in the first hour after it got wet. The next morning I took it to Vodacom Vincent in East London and they sent the phone in for repairs. A week or two later I got my phone back in a worst state that I sent it and get told that I dropped the phone that's why I have the problem but on the invoice it states clearly that the phone got liquid damage, witch I don't under stand the Sony Experia Z3 is a waterproof phone and was advertised as a waterproof phone. Vodacom just said you should have a insurance on the phone, is that not false advertising? After I got the phone back from the Vodacom repair I took it back to the Vodacom where I took the contract out and the maneger told me she will esculate the isue , it's been six months and this is all I hear from them nothing, I still pay for the contract