Cisco :: Enable MAC Filtering On WLC 5508

I am trying to block clients based on MAC addresses connecting to our Wireless Guest network.
 
My scenario is: We have 2 interfaces (corporate and a guest). Users are connecting to our guest network after they have automatically connected to our corporate network and logged into Windows. When they realise that things are not quite working in the way they want (access to servers etc...), they reboot and then find they cannot logon to the laptop at all. This is because the laptop has automatically rejoined the guest network and has no access to AD. I then have to locally logon to the laptop and remove the guest network.
 
It’s starting to become a bit of a pain as we are an educational establishment and... well... you would wouldn’t you
 
Hardware: WLC5508, Software Version 7.3
 
So far I’ve tried enabling MAC Filtering under “Security -> AAA -> MAC Filtering”, but found out that it’s a white list. The opposite of what I’m trying to achieve, but I like the fact you can link it to a specific interface.
 
I’m just looking at the “Disabled Clients” again under “Security -> AAA ->”, but think this is more a total ban as I cannot see a method at attaching it to an individual interface. I'm kindda stuck and my good old friend Google is not yielding great results.
 
I’m not by any means a wireless expert, so there is probably a better method. I would prefer to use the controller as a way of achieving this, but if you think I’m wasting my time and should be looking at a Windows Group Policy method then I’ll go with that?