Rees52 - Company not refunding despite taking back item

I had a drone race but the day before the race my drone's motors snapped, so I was desperate to get new motors in a day, so I started searching online. A salesgirl reached out to me, I explained her my situation and she said I will get the motors in *-* hrs if I order from their website. So I kept her on call and ordered from their site as per her instructions so that I get my shipment on time, but by mistake she shipped it through bluedart instead of porter (have proof of her acknowledging her mistake) due to which the motors came in *-* days instead of hrs. So I contacted their customer support, explained them what had happened, they understood and said I was eligible for refund. They sent a bluedart guy to pickup the motors saying that I will be refunded once they receive the motors. *-* days passed, I asked for tracking number to which I got the mail that it had reached and they were now in process of refunding. It was stated I would get the refund in *-* working days. Still when I did not get, I called, to which he gave me a deadline that by this time you will get your money back. I did not get, this process has been going on for *-* weeks now. Everytime he says "sir I am talking to the accounts team, you will get your refund by (new deadline)", which never happens. When I ask him to give me contact details of his accounts team, he refuses. This incident affected me ofc cuz I was the favourite to win the race according to everyone who saw me fly and missed out on a cash prize.