Deny Users AD on Freeradius + Wireless&VPN

Hi, We have a wireless network that uses freeRadius integrated with AD for authentication. There are some test user accounts on AD that I would like to deny access on our Wireless and VPN. I have tried "How do I deny access to a specific user, or group of users" on FAQ but it is not working. I'm guessing that this is not the correct method. Please help me on how to set-up correctly. Thanks! Roehl