I want to know what I should do about a situation that involves being scammed to scam someone without knowing?

So, I took a job I was offered like an idiot. It was offered through email and I shouldn't have but They didn't want any of my personal information really just my name address and PayPal email. The job was that clients would buy through them and the money would come to me through PayPal and I would have to transfer it to my bank, withdraw and UPS it to them. Unfortunately I did this. The client (from NJ) opened a case on PayPal because they hadn't received what the bought and want a charge back, however I don't have the money. I was paid $479 and I have $300 of it left , I'd just have to get $179 more and I could give it to the person back. The problem is that they paid $6,500 dollars for whatever they bought. I've emailed the people and they haven't replied back and I've called and the line is busy. I really wish I had not taken this "job" I feel more guilty that the person was tricked as I was. I've been having a lot of financial issues So I was blindly desperate.