Great Eastern Trading — Defective ac delivered after 7 days

We bought LLYOD Split AC on 15.04.2021 from Great Eastern Trading Co., Baguiati Branch with address 28/c VIP Road, Narayantala West, Kolkata-700059. The delivery and installation was meant to promised on 18.04.2021 and 19.04.2021 respectively. But it did not happen. After continuously calling up the number of salesperson Susmita, she insisted that the delivery will happen on 18th April itself. On 19th we visited the store, and then they informed us that the outdoor equipment is still in transit. After still continuous calls and visits to the store, they signed on the bill stating that the delivery and installation shall be done on 21.04.2021. At 9.35PM on 21st April, the AC was delivered as well as the service personnel came. When they opened the box, the blade of the AC came out and was hanging from one side. Defective piece. I am attaching the pictures in this mail as well as the bill. I need IMMEDIATE ACTION on this. Need full amount refund. We are struggling in the heat. My mother is an ailing patient of high blood pressure and they have completely harassed us since 18th April, specially the salesperson Susmita.

I am bound to take legal action against this if we do not receive the refund tomorrow itself. Will never deal with Great Eastern.
Awaiting response to this.
I tried to upload the pictures of the invoice and damaged product but there is some problem with the website.