If you login to the VPS Control panel or Web hosting server and attempted login fails 3x in 3600 secs, your ip will be blacklisted.
You need to reboot your home/office internet get new ip and access. Please ensure you are using correct credential when you login to the server.
If you still facing difficulty to access, please contact our support team and provide us your IP (https://cpanel.net/myip) and screen capture for our assistant.