Exchange and Windows 2000 licensing…

I just recenly started working with this companies servers. They have 6, W2K servers and 2 NT 4.0 servers. One W2K server is running Exchange 2000. Now when I open up the Licensing mangager it shows that I have 135 per seat allocated and 0 per seat perchased, and 146 per server reached and 0 per server purchased. Now I talked with the sale person who sold them the equipment and software and he has us down for purchased 150 exchange licences. How do I go about looking in to this further? HELP?