Samsung - Samsung fe defective product

I bought my Samsung S** FE on *th September,****. I payed Rs **,*** for the phone itself and another Rs **** for the insurance of the screen. The phone is IP ** rated water and dust resistant. The phone worked flawlessly within the warranty period. Recently on *th of November, ****(after two months when the warranty period and insurance was out of date) spilled a glass of water over the phone by accident and around after half an hour the cameras became foggy and then later that night the screen went black. (Which isn't supposed to happen on an IP ** rated phone). I handle my phone with utter care but just after the warranty period the phone got damaged by water just by accidental spillage of a bit of water. I immediately switched off the phone and let it dry for a day or two but nothing seemed to work. I have done my research and this isn't supposed to happen. I went to the samsung service center and they told my screen was damaged due to water damage(again a IP ** rated phone). I had to pay Rs **** for the same. The product is evidently faulty since a glass of water isn't supposed to damage the phone. The specifications mentioned that the phone can be immersed *.* meters under water for ** mins. The invoices are attached for the same.