I would try to get another HostGator support tech.
Are you able to log in to your domain's HostGator cPanel?
Are you able to log in to your domain with a FTP client like FileZilla?
If you are able to log in this is a good indication that HostGator is working properly.
It also verifies that your user id and password are correct. (I've set up dozens
of HostGator websites and issues on the HostGator side are rare.)
This leaves the XSite Pro Publisher settings.
*** XSite Pro Publishing Settings for HostGator ***
**Main Domain**
* Domain Name:
http://www.mymaindomain.com* Home Directory: (leave this blank)
* FTP Server: ftp.mymaindomain.com
* FTP Username: (from your web host email)
* FTP Password: (from your web host email)
* FTP Directory: /public_html/
**Sub-domain**
(Note that the subdomain folder needs to be created on the server side prior to publishing)
* Domain Name:
http://www.subdomain.mymaindomain.com* Home Directory: (leave this blank)
* FTP Server: ftp.mymaindomain.com
* FTP Username: (from your web host email)
* FTP Password: (from your web host email)
* FTP Directory: /public_html/subdomain/
**Addon Domain**
(Note that the addon domain needs to be created on the server side prior to publishing.
Look for the Addon Domains icon in the Domains area in cPanel)
* Domain Name:
http://www.addondomain.com* Home Directory: (leave this blank)
* FTP Server: ftp.mymaindomain.com
* FTP Username: (from your web host email)
* FTP Password: (from your web host email)
* FTP Directory: /public_html/addondomain/
Once you have your Publishing info correct, click "
Publish"