Consumer Redressal

We had purchased a Voltas AC in 2011, whose compressor had some problem within the warranty period. On complaining to the voltas customer care, they came and had taken the compressor for replacement but regardless constant folllow ups for 2 years we havent received the compressor. on 16 april 2013, two people from the company had come to take 3500 rupees against service charge and told the compressor will be replaced in 24 hours. it is 9th may 2013 today and after regular follow ups with the company they say the compressor is not coming, sometimes they say it is out of stock and all other baseless reasons. please help.