Samsung New AC not Working

Location/place: Mumbai

Name of company/service: Samsung

I had purchased Brand New Samsung 1.5 Ton AC , Model No : AS181SBFN , Sr No , AS181SBFNSTL on 29th Feb 2012 . Since then the AC outdoor unit is having a humming noise and less cooling .I had requested Samsung to provide me the replacement as i dint wanted to get a Brand New AC repaired . Its almost 4 months that Samsung is not able to provide me a replacement . Regards Dinesh Jarkani , 9820975844