Warranty Meaning

Guys I bought grand i10 last year February & this year in May the car engine broke down due to heavy rains in Cape Town(drove to flooded road at night)took the car to Hyundai N1 City, service advisor phoned me & told me i need to pay 85k for the engine to be fixed,i questioned them as to what is the warranty covering? Was told since there's water into the engine they will not fix the engine. Please explain to me what is covered by the warranty if this engine isn't covered by the warranty?i mean like i am paying a car that's standing.i will never again buy car from Hyundai.