Other people have had success with online chat for getting all devices deactivated.
They can't just deactivate some; they must deactivate all and then you reactivate the ones you still need.
You need to tell them to deactivate all your Adobe DRM devices.
You may have been unlucky with someone who didn't know about ADE and DRM.
Wouldn't it be good if Abobe provided a proper web interface to view and edit your activations?