Carrier Midea India — faulty air conditioner and not responding to complaint

We purchased an ac on 15 april 2019 and it didn’t worked properly. We raised multiple requests to change the unit but they trying to make fool o[censored]s giving timeline of 1 week ahead. They told to change the pcb of the product but no one came over.
We need strict action as they are not properly responding for the complaint again their own faulty product which needs to be replaced