Sony Xperia Z3 Water damage

27-03-2015 upgraded to a Sony Xperia Z3 . The reason why I decided on upgrading to this phone was because it is WATERPROOF!! I rinsed my phone with tap water just to clean it in a way. Just after my screen went of just turned black and I couldn't't do anything with it. Next day I took It back to Mtn were I bought it and they told me that they cant replace or repair it. The \so"called Waterproof phone was not Waterproof after all! They stated on the adverti*****t that was shown on television that this phone can take photos underwater"