Amazon application - Not initiating return

Hi,
We purchased a nilkamal mattress online from Amazon application but the mattress is of wrong size to our cot and not fitting the cot properly and hence we requested to return the product in its original form to Nilkamal and they have accepted the request but we hav to initiate from Amazon application since we ordered from that application only and the Amazon is not initiating the return even after looping them into the email conversation with Nilkamal and the confirmation from them is given. Please help us on this issue.

Below are the order details.
Purchased platform: Amazon application
Order no: ***-*******-*******
Registered phone no: **********