Your manifold was what started the this issue. Your posting get PJ kicked from NICO and KA-T.org, and got Enthalpy to sever ties with him.
However, legally.. there are only 2 ways you can get your money back. First, is if you paid via credit card, contact the credit company. Usually after 30 days, you need to write to them and dispute it. Or, sue him. However, there are additional costs that won't get reimbursed in most cases.. like travel to wherever he is. Lawyer and court fees are usually included in a judgement.
If you went through paypal to pay PJ from your checking account, I'd do a chargeback from your bank, if that's possible. Paypal's 30 day limit isn't good enough for every situation, including this, where a buyer expects to wait 30day to get a turbo kit. Whenever someone doesn't have a product in stock, DO NOT use paypal.. or if you do, pay with your credit card.
So.. if this didn't help you, I need more specifics, like how you paid, how many emails do you have, did you save them, ect.
However.. you need to make your own thread about this, I think.
-Jeff