Add Domain error: Sorry! Free domains with extensions such as .tk, .cf, .ml etc., are not supported.

Add Domain error: Sorry! Free domains with extensions such as .tk, .cf, .ml etc., are not supported.

I just signed up on saturday and I'm having trouble trying to add my domain.  I get this error 

Sorry! Free domains with extensions such as .tk, .cf, .ml etc., are not supported.

But the domain is a standard .com domain....coveyboost.com. I sent an email to support saturday and haven't heard anything.  

What's the right course of action here?