I completely agree. MSN are in desperate need of a system that allows agencies who manage & refer Adcentre business that is not billed via the agency to function & prosper (as Yahoo & Google allow).
We have an account manager who can manage accounts billed via ourselves but cannot assist or advise on business (the majority of our clients) who are billed direct.
We too have had Google only clients being offered vouchers by telesales companies (Base Connections) working for Adcentre which the clients ask us to use. We set these clients up within a billing account only to be told that the vouchers are unusable unless we create (yet another) master client account.
Please sort it it out. You & we are looking stupid.