Defective AC Supplied by O General

I have purchased O General Inverter AC in March 2017 from authorised dealer of O General. But when I started using it in July’17, It was not giving cooling. Right away I have complained matter to the dealer, but he hasn’t given any satisfactory reply. Than I have written a complaint to customer care of O General in July 2017. But the matter was not resolved. From than onwards I am again and again complaining about the issue to their dealer as well as to the company, but nothing happened. Now they have closed the complaint by simply saying that now your AC is out of Warranty. I feel cheated as I was supplied a defective AC.