Deleted AppleID cannot be used for Custom Domain

I used to have an apple id whose email id was in my own domain - name@mydomain.com. It is the main email that I use. This apple id has been deleted. Now, when I wanted to join my own domain to icloud and use this e-mail address as an address in this domain, I get a message that this address is assigned to the apple id (actually it was because the apple id has been deleted). Is there any way for apple to stop blocking this email address?

I was told by Apple Support I had to wait a year for it to be released but I have read forums saying 30days.

It is my email address so I don't understand why I cannot decide what happens with it.