[Resolved]  Koryo — Storage water heater (Geyser) Model NO-KWHZF25Y

I don't Have Bill, But I have Manual booklet and geyser box, Last 18 months back I purchaged this geyser, inside tank was getting leak, I request for service, service engineer visted and he suggested to replace the tank, to replace he demand bill, this geyser I purchased from Old madrass road Big Bazar, that bill now nothing is visible. but i Have manufacturing serial on please find manufacturing date and replace the tank becouse that tank have 15 yrs garantee. please letme know how can deal this issue. My m, No is [protected], mail ID [protected]@yahoo.co.in.