wrong information and missguiding

i bought a sony experia z3 cell phone last march 2015 whose imei no- 355098060074296 the company claims that the phone is water proof and as per the company it is ip68 which promises to go under water at a depth of 1.5 m and stay there for 30 mins but while i was testing the water proof facility of the phone i kept the phone in a bucket of water which has only 3 liters of water for 3 mins unfortunately the water gets in the phone lost its power now the company tell me while checking the phone that the company dose not bear liquid damage how dose it make sense a water proof phone dose not give warrenty in liquid damage. now the company is telling me that it will cost 34000 rupees to get my phone fixed .
i completly feel cheated by such a big brand sony by giving us wrong information about the phone and misleading us about it. please help