Reliance Digital - Post sale service denied

I brought Panasonic water purifier with a *-year warranty (****). This product was defective since installation with multiple episodes of the water leak. Reliance digital denied repair stating that it due to mechanical damage (due to high water pressure in tank) which is not covered. We repaired it with our own cost. Now the company is denying regular service like the change of filter which is covered by warranty. The reason given by the company is they give only one year warranty. But the warranty card provided to customer states warranty period is * year, not * years. We were cheated by the company by not honouring the * years warranty agreement which was assured at the time of purchase. We are also suffered by buying an inferior quality product which will not withstand normal water pressure from the tank.