From inside the portal you can increase the quotas for your Cloud Backup PLUS accounts. Search for the account via the search function on the right, or go to “Customers” on the left and select “View Cloud Backup PLUS” customers.
You will see two places where you can change quota, you need to add the figure into the second option, this will set the quota on the vault. Swap it to “restricted” and then add the quota amount and press “save”.