Refund scam. What can i do?

[Kamimiami]

Hi all. Just encountered a scam. I made a transaction on a third-party site, exchanged currency and received money on Paypal. But the next day, the sender asked for a refund from the support service. He created a fake screenshot, allegedly I sold the iPhone on eBay, they sent me money, and I disappeared. But I didn't have an iPhone and I don't have an eBay account. I exchanged currency, sent money and received it on Paypal. And now the scammer is trying to get them back with a fake screenshot. What to do and how to prove that they are trying to deceive me and steal my money? 

[sharpiemarker]

@Kamimiami 

Do you have a email or a receipt from third party website that you exchanged money? Exchanging money sites are very high risk. Contact customer services and explain the situation to them and upload pdfs of receipts.

https://www.paypal.com/rs/smarthelp/contact-us      

Scroll down to click “Message Us” or “Call Us” option on the bottom.

Or reach out to PayPal at Facebook or Twitter:    

PayPal on Facebook

PayPal on Twitter

[Kamimiami]

Yes, i have all proofs and screenshots. I even found REAL AD on Ebay, that proofs, that scammers screenshot is fake.