I've been dealing with web hosts for the last 18 years. Not once have I ever dealt with a problem like this with FTP. Each time I try to connect, it says "no such host is known."
User name: firstname.lastname@example.org
It's like this on all FTP clients. I've read that GoDaddy is pretty horrible when it comes to FTP. I hope not, but so far it seems to be the deal. Has anyone dealt with this same issue? If so, how did you fix it?
I'm assuming you have given DNS propagation at least up to 72 hours before trying via DNS? Have you tried via IP?
Were you able to call support and get your FTP access resolved? If not, this article may help you with your FTP access and ability to connect with the server and see your files. From reading your previous post, we see there may be a few errors. You do not need the prefix/subdomain of "ftp." and take care that the user name and password is not the same as that used on the GoDaddy account itself. The article will advise you as to where to find these details.