Are you attempting the factory default via SSH or via the Console? The "reset" "FactoryDefault" only works via the Console, and not via SSH.
Here is a link to an article that explains the process.
You should be able to use the AP discovery tool to reset the AP7532. If you reset the AP with the discovery tool make sure the AP has been up an running less than 10 minutes (reboot if necessary), otherwise the discovery tool will not be able to communicate with the AP.