Did you use www.yourdomain.com:81?
You HAVE to use :81 as that is the port that the ISPC web panel runs on. Just typing in the domain won't bring it up. It has to be yourdomain.com:81. Typing in the domain alone gives you the default web page, such as your hosting companies webpage that you set up. Adding :81 at the end of your domain takes you to the ispconfig control panel.