I think paypal is your friend's best bet as a starting place. They do guarantee more than just ebay. They also have access to reverse the transaction. The bank is not going to be of any help. They just paid a transaction that was initiated by your friend through another financial institution (paypal).
Hopefully your friend will receive the PSP's or his money.
I'm writing this for one of my friends. Anyway, about 3 weeks ago, my friend went onto shoespop.com with no knowledge that it was a scam site ran by a group of people from China, and paid