Samsung Galaxy - Galaxy Faulty

Dear Sir
I had purchased Samsung S* mobile on dated **.**.**** still the product is under warranty ( taken extended warranty by paying additional amount) but as now facing problem of battery backup & display malfunctioning and to rectify the same went to your authorized service Center at Sector **, Faridabad but Service center Claim that problem occurs due to mobile get moisture & not considering the same under warranty (service Complaint no.**********) and asking for too high repairing charges..but during buying the phone Samsung Claim that The Samsung Galaxy S* is rated IP**, using the Ingress Protection rating system & this is an water-resistant handset(also mentioned at Samsung website) kindly Clarify how come your authorized service center is denying to consider the same under warranty kindly look into the matter & treat the same on priority basis
Details of mobile Handset are as mentioned below
Product model no.-SM-G***FZKDINS
Product Sr.ni.-RZ*K**TSGRD