They always say that they'll explain when they get back home or when they have access to their computer or when they're done shagging their dog but the truth is, it wont happen. Sorry for your loss buddy.
I can write the next reply for Robertt, exactly gonna know how this is playing out.
"It's different this time, I really didn't scam anyone.
I've received the PayPal funds from another account myself. I traded with
user X, Y
BTC for $Z.
Only today I realized that the funds I then sent to you guys have been reversed. I wasn't the initiator of this.
I'm a victim aswell here. Believe me!"