Harrasment for servicing of ac

The ac was installed in may,2014.After installation,we felt that the cooling was not upto the mark.The area where the air flows gets cooled and the other areas remained higher temp.When the ac is turned off the cooling effect vanishes immediately.When we complained about the problem,they sent an engineer who said it was perfectly okay.After that was rainy and winter season,so the ac was not in use.Now when we are using the ac this summer,we are facing the same problem.On complaining again and again they are not at all listening to our problem.Last on 11.05.2015 we lodged a comp0laint.They had sent an engineer on 14.5.2015 who without checking properly confirmed that there is a problem.He had said after going back to office he would give feedback.But after going back he closed the complaint id (id-91344493) stating problem resolved.Then we had called the customer centre which connected me to ADREAM services,which handling our problem.On talking to that same engineer he confirmed that our ac has no problem.on requesting the customer care executive connected us to higher official named Mr.Sanjeev Verma (from delhi),who said the service would be paid one if they send engineer to verify as the warranty period is over.So is the paid service solution to our problem? what do they do when we face problem during the warranty period?They are in no mood for resolving the problem.This company charges huge for their products but is worthless on after-sale services.We have been harrased too much by this company.