Apologies for any confusion.
My 1st point - on my OXD Dashboard I have a 'Primary Contact' listed under billing Administrators.
This 'Primary Contact' has since left the company, so I need to remove them and add in a new 'Primary Contact'.
My 2nd Point - I need to add an additional user to billing Administrators, this user has a separate account on OXD. How can they be added to my (the main company) account?
As when I currently try to add them it states the user already exists.