In terms of the timeout, if you submit an incorrect password 5 times, you are blocked from logging in for a minute. Another wrong password increases this to 5 minutes, then 12 minutes and 30 seconds. After this, you would simply need to change their password.
There're two ways of restoring account access - you can update their StackCP password manually via the following webpage (you will need access to the registered email address): https://stackcp.com/recover
Alternatively, we (VisualWebTechnologies tech support) can set a new password for the user within our Cloud admin control panel, which will immediately lift the restriction.
Important: Please use your email as your username when logging in the StackCP dashboard.
Best wishes,
Bhavnish and VisualWebTechnologies team