Let me clarify - you can "appeal" a claim decision - my suggestion is to do this with a "live" person rather that online. Paypal has a "dispute resolution" / "Claims" department (not sure the exact name) that is US based and the trick is to try and get connected to them directly. The regular CS is usually based overseas and reads from a script.
You should call them and insist on speaking with someone in the "Claims" dept - if you do not succeed at first - try,try try again..!
If you do end up speaking to the right person, make it a sob story and do not in any way suggest that they are trying to cheat you - yours truly speaks from experience!
There is a also a paypal user forum - here is a link for the "disputes" thread:
www.paypal-community.com/t5/Disputes-and-Limitations/bd-p/5
I can understand your anger and frustration but this has nothing to do with predatory behavior on part of paypal. CS / Support has been automated to a ridiculous extent at most companies that a Live person rarely gets involved unless the matter escalates. A lot of us have learnt the hard way that "AI' in not very "I" and can be very "A" most of the time.
As a general rule (and for future reference) Paypal Buyers Protection claim is more likely to be successful if you bought from a known merchant or intermediary (like ebay) as opposed to a person to person transaction for the simple reason that a P to P claim is more susceptible to misuse / fraud.
Good luck and let us know how it plays out.
Cheers!