Amazon - Refund not issued

Order # ***-*******-******* on Amazon.in
I have ordered a laptop with exchange offer on *th of September **** by paying Rs. ***** through UPI (Google Pay) immediately and it was supposed to be delivered on the very next day i.e. *th of September ****.

DD/MM/YY Format
**/**/** - Made the order by paying immediately through UPI and the payment was successful
**/**/** - Supposed to be delivered but was not delivered and the order on Amazon has not moved to/past the shipping stage
**/**/** - Since it was not delivered, I have requested them for cancellation but due to technical glitch, they couldn't cancel the order and asked me to wait till **/**/**
**/**/**** - Raised a ticket through Customer Service regarding the same and was asked to wait for *-* business days
**/**/**** - Was told that the ticket raised on **/**/**** was to the wrong fulfillment center so this time, it will be raised to the right one and was again made to wait for *-* business days

Similar tickets have been raised multiple times with each time being a ticket for different issue and as on date of today being **/**/**, I still have not received the refund.

Hundreds of calls and tens of hours of speaking to numerous associates through customer service helpline with no resolution has been and is mentally exhausting. Also, the amount itself is huge so I am facing financial issues too.