FYI, you only have 45 days to file a claim through PayPal... after that, they will basically tell you "tough luck". Even if you file within that window, as long the seller shipped you *something*, PayPal will also tell you "tough luck". Basically, as long as the seller ships you something with a tracking number and does it within 45 days, you're not going to get any help from PayPal.
You'll have much better luck going through the CC you paid it with... hopefully you paid it with a CC and not PayPal funds. This is why it's ALWAYS better to use a CC through PayPal than PayPal funds... it's a common "scammer" technique to give sob stories about family in the hospital, themselves in the hospital, loss of job, loss of car, "too many orders", blah blah blah... until the 45 days are up, at which time you have no recourse through PP. Even if my some miracle they did find in your favor, if the seller has pulled the funds, they will tell you "tough luck".
I am heavily involved in the reptile/invertebrate keeping hobby, and we see this CONSTANTLY... if you have ANYTHING leaving a sour taste in your mouth, demand to see a tracking number immediately. If he can't produce one, he's lying to you and you should file your PP claim before he has a chance to transfer the funds out of his PP account. Filing the claim will freeze his account so he can't do that...
best of luck, hope it's an honest case of getting behind... given my experiences online, I'm going to confidently guess that it is not.