Appario Retail Private Ltd - Wrong product delivered

i ordered a product Sony WF-****XM* from the amazon.in from seller Appario Retail private limited on **th January **** and it was delivered to me on **th January ****. when i opened the product it was a wrong product delivered to me ( Sennheiser momentum wireless *) . i reported to amazon customer service and shared all required photos what they asked to me. After all validation done they arranged a return pickup and on **th January it was picked from my side after all checking and validation by the pickup boy. On **th January it reached the seller. Now amazon is saying that all the delivery and refunds are handled by the seller and seller only initiates the refund. seller has taken back the product and also not initiating the refund to me.