On a new machine, make sure you are signed into the exact same platform account where your game was originally installed, and you saved your save game to the relevant cloud.
Go to the 'Load Game' and select the 'Cloud' tab to preview all your cloud save games. Select a save game and then the 'Load' button to load your save.
You must have an active Internet connection to use the Cloud Save Settings.
If nothing above works, please submit a support request stating exactly what you've tried so far, and a member of our team will try to help.