Out of Policy return for high value order - what to do?

• I have a high value return request for a 'out of policy' order placed 49 days ago ,

• buyer return reason code is that the item is defective, order value is £600.

• This return was not auto approved by Amazon, (I believe because of 'out of policy' status.)

• I'm aware that normally unapproved returns in a timely (48 hour?) window run the risk of A to Z case and best practise is to normally approve returns but this usually is done for me if the order is within the refund period.

• Buyer has been contacted at least 3 times with no reply to get in touch with more details of the fault/defect so we can arrange a free repair/replacement under warranty, have not offered them a refund to us but a manufacturer warranty repair/replacement on the item - no reply from buyer.

My question is - even though I always have the option to 'close' returns but never do use this option as I feel its a trick for in policy orders, but what about out of policy, is it a con also, if I deny/close the return request does the buyer get a open door to A to Z case despite having messaged them the offer to repair/replace their item, which Amazon bots won't probably see or realise.

Or Should I just cave and approve the return even though they're 2nd hand goods - with most likely nothing wrong with them and missing packaging , scuffed/scratched etc etc.