I'm on the phone with Godaddy. You can try
fraud@godaddy.com. I think you will need to provide all the information about the scam
Dispute on transfer away form
https://www.godaddy.com/gdshop/pdf/TAdisputeform.pdf
This form is when someone has tranfered your domain away from you to another registar without your approval, but it may work in your case. I would explain what happened and ask that they make the scammer provide proof of payment.
Ok, the support rep got back to me and she now says that since the change of ownership was done at 0 dollars, it is a matter between you and the "buyer".
I would still try using that form above, but since you did approve the transfer it may not be effective.
I tried the phone number that you were given and it doesn't work now.
It's good that you reported this at Internet Crime Complaint Center as mentioned above, but I would also call the Miami police department and file a report there as well. Save all emails from the scammer. If you need some help with trying to track them down and gathering more information, please let me know, I'm glad to help....!