How tp get seller to return my items that were sent to them for refund but the refund was declined

Description

I purchased two evpads from Gadget Australia but one was defective so I contacted PayPal for the refund of the delective evpad ($180 AUD) and PayPal sent me a message stating that the seller had agreed to refund both items a total of $430 AUD provided that I return both items and with proofs. I had done that but the claim was declined for some reason. So I have sent a few email to the seller asking for the return both of my items in working order. I hadvenot received any reply from the seller. what should I do?