PayPal chargebacks

[Bird Legs]

In August I sold goods from my eBay shop for �11. and then a few weeks later was informed by PayPal that the customer had disputed the charge with his credit card co.
Although a normal eBay/PayPal transaction he denied using his account name and security although goods delivered to his registered address. Then PayPal informed me that I would have to bear the investigation cost and charged me �7. Today I got news that they had closed the case leaving me �18. out, and could only suggest that I contacted customer direct. On getting out my transaction details I discovered that this person had done the same to at least two other sellers.
I have sent an email invoice for �11 + �7 + �5. for my expense to the buyer and informed him that I intend to contact his local police regarding fraud.
Any suggestions what else I can do?