There could be many reasons why you are unable to access your cPanel, WHM or Webmail.
1. Your IP address may be blocked by the firewall due to trying the incorrect username or password to may times. If this is the case you can log a ticket through http://www.mysau.com.au, if you have access to email please send an email to email@example.com or contact our support team on 1300 788 862 and please provide us with your IP address in which you can obtain from http://ip.mysau.com.au
2. Most networks have a firewall setup to block access to the ports required for cPanel, WHM, and webmail, in which you can visit our "Proxy Access for cPanel, WHM and Webmail - Needed to Bypass Firewalls" article to get in.