Amazon India — Cheating/fraud by taking return products and denying refund

The product amazfit t rex 2 smartwatch was purchased from amazon app on 2nd July. Order was delivered on 8th July, it was found to be defective and after investigation from amazon team they agreed for return and refund. After the delivery agent appointed by amazon picked up the item and verified it also.. Even after 10 days I didn't get refund upon continuous follow up on 26th July they are stating item returned is incorrect. And shocking thing is they do not have any proof on the same and they are not ready to share any investigation report or even a photo of item they received. Simply denying based on no proof whereas I have proof of successful pickup from their delivery agent.
My order ID is[protected]