I can't delete custom domain email addresses from iCloud+

I recently gave custom email domains for iCloud+ a try, but now I'm having trouble getting rid of it! I managed to delete the address for my custom domain from the iCloud+ Features webpage, however, it's still showing up on my iCloud Mail page and in the iCloud settings on all my devices. This is causing some serious issues with both sending and receiving emails from my custom domain.

I have gone through all the articles about setting up and taking down a custom domain iCloud+ email address and nothing solves the problem.

Can anyone help me out here?

I've added some screen shots to illustrate the situation.