If it wasn't recorded it may take a while to get there. There could also be issues regarding size x cost. Like you said, one guy mentioned you need to use parcel force. The PO have been having strike issues recently too. The buyer sounds like an impatient git! For him to dispute it with Paypal so soon is ridiculous. Did he not mention anything to you before hand? I'd complain to Paypal. He might get it tomorrow and Paypal have your money. If he keeps quiet he gets refunded too. Keep the buyer sweeeeeet!