Bluestar Ac — Brought new ac which is faulty

Address:	Erode, Tamil Nadu, 638001
Website:	Bluestar

I brought a new Inverter ac in tamilnadu on 15/05/2017 for Rs45.000/- but while on installing the AC the outdoor unit doesn't work so technician had changed the board on indoor unit and still it doesn't work so then they were trying to change the Main board in outdoor unit So because i brought a AC as New so i want to have a replacement AC i dont want this faulty Machine But they were not ready to offer me a Replacement Machine.
So i want to know about the Return and Replacement laws by which i can get a Refund or a Replacement Unit
Iam looking for the suggestions