Return Question

Hello!

Curious how to go about this situation. Buyer received 2 desktop speakers, one of them is defective and is returning it. There was another return submitted, so I reached out and it was due to him forgetting to include some of the parts it came with in the first box he sent back.

The buyer asked if I can send him a replacement for the defective one, which would have to be done through the manufacture. Even though he asked for this, per Amazon I still have to issue the refund when I receive the items.

If I get him a replacement, do I still have to issue the refund? Or should I contact Amazon to see if they can change the return to an exchange someway.