Unable to leave claim evidence

Description

Hello Hoping someone can help. I have had a claim started against me where the buyer is saying that they have not received the item they purchased from me via eBay. I had provided full tracking and signed for details and photos via email on Ebay at their request as the package was delivered and signed for at their address. They didn’t get back in touch but filed a refund claim via Paypal (not Ebay) I keep trying to provide more details and respond to Paypal response request but it is never registering or uploading (so frustrating!! ) and I am running out of response time…..I don’t know what to do. If the buyer is saying they haven’t received their package yet all the postage evidence is showing they have, I don’t feel responsible for the refund but feel they should be making a claim to Royal Mail. Can anyone advise. Kind regards