Follow these steps to delete a user in case you are getting error: User Account Removal FAILED! User account folder still exists!
1. If you have root access, SSH to your VPS using root.
2. cd /home (go to home directory)
3. rm -rf username (remove folder for the user)
4. Now delete the user from CentOS Web Panel (CWP) so that DNS records and other data can be removed.