Sony Z3 not waterproof as advertised

Sony claims Z3 is water proof up to 1.5meter for 30min in fresh water with all ports closed. My Sony Z3 landed in fresh water and got water damaged while all ports were closed, I sent the device in to Vodacom to test, they just confirmed device was Beyond economical repair. I sent the phone to Sony specialist SSS Cellular at my cost, they tested the phone and confirmed waterproof system was functional. I conducted my own test at 1.1m in fresh water with all ports closed and I noticed bubbles from the device not near the ports but at one of the corners of the device. Sony refused to replace the device, I differ, I am of the view it is a manufacturing fault on the device, The device has not been abused and was merely 4 months old, with rubber backing and screen protector on since day 1.