Unfortunately items are stolen all the time, couriers / posties deeming a place to be safe turning out not to be safe, but this is not your problem, as it's out of your control where an item is left.
If you have tracking to show delivery to the name and address eBay provided on the order details, entering those numbers if not already entered, into any case the buyer opens, will close it in your favour, no need to refund.
Send the buyer a polite message explaining this, and to ask their postie where they left the item, it might even be still there and well hidden ? !
@completeneatfreak
