Installation issue. Review on Carrier Split AC 1.5 Ton

This rating is not for the product since i am not able to use the same till dates as installation of the product was not completed after receive the product it took three day's for engineer to come installation when he came he pointed out that there is some defect in the draining pipe and they are unable to complete installation further he added that replacement of same doesn't come under their scope you need to register a new complain when i called carrier customer care they spoke to installation engineer for replacement of same but he denied the same and asked me raise different complaint for same as advised i raise a complain but when carrier technician arrived he also refused to replace the faulty part and said it is to be done by the person who installed however he repaired not replaced the faulty part i am confused that who will replace that part