@carolinebennett,

Once a request for refund has been made on the basis of SNAD/INAD, the correct course is for you to provide the buyer with a return label. You can also reply within the dispute along these lines:

❝Dear [buyer]

Thank you for getting in touch with me about the [item name], item number [xxxx] which you purchased on xx/xx/xxxx.

If there is a fault in the [item name], we will happily refund once it has been received back by us. We carefully inspect all items prior to listing and again before despatch, but if something has been missed, we will double-check and resolve as quickly as possible.

Please send back the item, and we will contact you again upon receipt of the item.

Kind regards,

[seller]❞

Never - NEVER - refund before the item has been received back. That would result in no pressure at all upon the buyer to return your item, and there willl also be no consequences to the buyer's failure to return it. You can't give the buyer negative feedback; there's no way to warn other sellers; in short, it's gifting the buyer with your item, putting you out of pocket, and there will be no cathartic release to soothe your annoyance or frustration.

You should only refund upon receiving the item back, and inspecting it. You have three business days after receiving the returned item before you must issue a refund.

Read through this Help page about How to handle a return request as a seller.