Exploiting Player Up has disappeared with my money

Buyer and Seller are left waiting over two weeks while Player Up does nothing. They have my money, they will not push transaction throogh, they will not refund money, in fact, they are flat out ignoring us and our requests for resolution. Flat out unacceptable - never again. Oh wait, I forgot - they occasionally respond, but its a sripted response from a bot - which obviously does not fulfill our need. What to do? Swallow the loss and kick rocks? Plan revenge via ddos/rat? Report them? (to who???) Or keep whining and moaning about it accepting the lock of progress? I do not like any of those options but unfortunately I've been conduction the latter....fuuuuuuuuudge!