Amazon.in - Toys delivered instead of INR DJI Mavic Air drone

I ordered a DJI Mavic Air drone from Amazon.in during the great Indian festival. The amount I paid was INR *****. However, I was shocked to receive * toy helicopters (just worth INR ****). The delivery was performed on Oct **, I raised a complaint to Amazon.in customer care, sent them pictures through email, they said they will investigate and come back after *-* days. However, I have not received any update on my issue. They even cancelled my refund/return request saying that it will be processed only after their internal investigation. Given the significance of the issue, I am very disappointed with Amazon.in support team. I have wasted lots of time and faced mental trauma because of this order from Amazon.in.