I'm not sure about all of the correct url's at Frihost, but it looks like frihost.org is not right. I thought it might be frih.org. That didn't work with your subdomain name, but I tried cp.frih.org and it requested my credentials.
If you click on the word "Account" which appears on most page headers, you should get information about your site and how to log on to the control panel. On mine, there are three different choices given, including one using an IP address in case the dns is messed up. I hope one of those will allow you to get to the control panel. If not, there may be a server issue or something wrong with your account that only an admin can fix.