If you would like to block certain numbers so that they cannot be dialed from the system, you can do it from Disabled routes.
Navigate to Routes -> Disabled routes and type in the numbers that you want to block.
Destinations should be separated by new lines.
Regular expressions can be used by prefixing the destination with "_" (e.g. _^001[2-9]).
Please note that any numbers that you enter into Disabled routes will be blocked on all system levels.