Here's what I'd do it in my company.
It is not the customers fault, so they should in no way be held responsible for anything, and not be made to pay anymore charges. "The customer is always right" is correct for good customer service even if they are wrong. In this case they are not.
You are responsible for the package to get to the customers door, no one else. It is you who selected the delivery company, no one else.
Learn from it, use another distributor, apologise to the customer, and inform them you are sending it again.
Always ensure you use a service with adequate insurance cover, and a tracking code. If you send packages a week, open an account with DHL or something. Also looks professional on Ebay, putting in bright letters "All deliveries via DHL"
