I would email the buyer and tell them unless they close the dispute in your favour you will be going down to the police station with the packaging and a stat dec to have them investigated for obtaining goods by deception.

If it is a Paypal dispute then often, after asking to speak to a supervisor, a stat dec is all that is needed although sometimes they will require a crime report number. If they still refuse to cancel the dispute in your favour tell them if the money is not back in your account within 48 hours you will be contacting the ombudsman with all your evidence. That almost always does the trick.