Tracked parcel delivered to 'safe place' - recipient not received it

[Lemon_coffee]

Hi, I'm hoping someone can offer some guidance on what I can do in this scenario. A recent buyer on Etsy has sent me a message asking for a refund because their parcel was delivered to a 'safe place' and according to them it's not there. They live in an apartment and I would guess from the photo that it's probably been left in a communal area. I've asked them for a few more details as their message was short, simply stating that the parcel isn't there and that they want a refund.

The parcel was sent via Tracked 48, so I have a photo of where it was left along with GPS coordinates. I've advised the recipient of this and asked them to let me know if they recognise the location shown in the photograph, plus whether it's a safe place they have previously requested Royal Mail to use. I've also asked them to check with immediate neighbours as they made no mention of this. The parcel was delivered 4 days ago so it must be around somewhere.

Would I have any hope of being able to claim with Royal Mail for the loss of the parcel if it doesn't turn up? Since this is showing as 'delivered' I've got a horrible feeling they'll just deny a refund.

If anyone can offer any guidance I'd be very grateful!