Undeliverable ... and uncontactable.

[xdm]

I sold an item and shipped it via Priority Mail.  Unfortunately the Paypal address was wrong - it appears that the buyer omitted apartment number.  I have been trying to contact the buyer with no luck - no response.

However apparently a chargeback was indeed placed against Paypal.  I got a hold on the money paid for ... 8 minutes ... and it was decided in my favor because I shipped on time and provided tracking.

However the story hasn't quite ended yet.  The item should be back in my hands due to Return to Sender in a few days.  So then I'll have both the money and the item and no direction.

I don't want to be responsible for the shipping paid, and, I really don't want to be responsible for the final value fees as this was a no-sale as I can't even charity ship the item (since I don't have a valid address).  How do I proceed from here?