Just for your future records: YOU as the seller are responsible for all parcels until they reach their intended customer.
Paypal/ebay consider the carriers your business partner and hold you liable.
Ebay can get your money back when you appeal the case if order is held in custom.They refund money to both buyer and seller.But paypal is another thing.
I find it hard to feel sorry for you upon reading this post when the greddy boost controller you sold me was faulty and I contacted you with a view to an exchange and you agreed. Upon receiving my returned controller.......sent registered!! You stopped all contact and never honoured the return. You are a terrible ebayer!
I had same experience. PayPal does not care if a customer refuses to pay customs, just "Not delivered" and end of story. The best is to ask FEDEX to send it back, at least you will not loose the item, just will loose the shipping cost.
re: PayPay took me up for 6000$ 
