How does a business manage their account?

Trying to purchase licensees and assign to our Users but there are no directions on how this is done. Lots of scares about once it is assigned it’s stuck. I don’t want to buy something and find out I can’t assign it to a User or if they leave the company I don’t want to depend on Trimble getting the license back for me since they don’t return calls. Tried calling sales support but they don’t ever call back.

Here is a link to the official help article for account management it should have the answers to your questions:
https://help.sketchup.com/en/licensing-accounts-and-administration/managing-sketchup-subscription