Z3 Sony experia,false advertising

Found out The Z3 its not waterproof as advertised by sony,even my service provider claims its not.The phone was held under tap water to clean off some sticky residue on the screen,i had the phone under the tap for less than 3 sec after insuring that all preconditions stated by sony was met and even dried it using a hand towel.The screen went black after few seconds.(damp stickers still original colors,took pictures).Phone Sony head office and explained the situation.After returning the phone to My service provider for repairs/diagnosis I found out they are not willing to repair(BER).I contacted the repair centre to provide me with some kind of proof as to where the water came in and they could not tell.The phone has been to 3 different repair centres and still no feeback or report.The phone was then never really tested for air tightness as its should have been done before striping the phone.This is unacceptable,how are they not willing to replace/repair the phone if they messed up and cannot tell where the water came in?Obviously a defective phone!been trying to contact my service provider since 23/11/2015,no luck,even emailed them.Vodacom zewenwacht CPT.Sad part im still paying