Need help with a buyer message

A buyer Purchased an item from us Yesterday. They then messaged us straight away saying the item was damaged and sent us pictures of the item which looked similar to our item even when our item was due to be delivered following day. in message they also wrote “they wont be able to return the item as they are away and wont be back in country for 2 months. the buyer told also wrote that they are looking for full refund without returning the item or else they will leave negative feedback.”

when i was about to reply i received another message apologising and saying it was for different order and not the one that was purchased from us. which is fair enough however once my products were delivered to the buyer today. I got Exact same message but without pictures. they then told me they cant send pictures.

I have messaged them saying the items need to be returned and we will get them collected however my concern is they will leave negative feedback and will open A-z Claim. i wouldn’t have bothered if the item were cheap but the items are expensive.

any help would be much appreciated

Thanks .