Freelancer Scam, Slander, and Falsely accuse of not compensating a contrator Internet

I hired a contractor with the name MD Rayhan through freelancer's marketplace. He does some work and I made payments to him. Freelancer locked his account so he could not receive my payments. He then accuses me of not paying him so I contacted for a refund. Freelancer will not refund me or give my payments to Rayhan for his work. Rayhan then tells me to pay him what would be double by paying again. When I refused, Rayhan puts on my social media accusations that I refused to pay him and is calling to action a group to make a law suit against me. This whole time I am talking to freelancer who continue to refuse to refund,and refuses to do anything to recover property this guy deleted or damaged. I lost my business facebook page, and had to delete lots of posts that he put in my accounts. I am continuing to deal with this that is all thanks to using Freelancer to hire a "professional."