I eventually found a solution to the problem. They Macs were all showing as "assigned" not as "pushed". Wiping the OS and reinstalling was not an option on the particular machines I was working with. I did try booting to recovery and doing an OS reinstall, but that made no difference. Ultimately running the following command to force the iMac to install the DEP enrollment profile:
sudo /usr/bin/profiles renew -type enrollment
This works great if your Mac has never been enrolled in DEP before. If for some reason you are trying to re-enroll a mac this will probably not work. But if you are enrolling a mac after installing the OS and configuring everything, this will get you out of hot water so that you are not forced to wipe it and reinstall from scratch. Hopefully this will help someone out.