username@plus.net no longer works

[#1]

When I first signed up to plusnet, some years ago, I had the email username@plus.net.
I have also created  '@username.plus.com' mailboxes later.
But now the @plus.net account now seems to have disappeared!
Has that happened to anyone else?

[#2]

I think the .net style is now restricted to staff.

[#3]

We haven't allowed customers to use @plus.net as an email address in my time here at Plusnet as far as I'm aware. The email addresses for customers have been mailbox@username.plus.com for a long long time.

[#4]

I have similar problem, need help please.
I still log in using "username@globalnet.co.uk".  Globalnet got swallowed by "madasafish".  The fish got netted by Plusnet (BT).  My mail account is now  username(1&2)@username(1).plus.com .
I would like to give up the globalnet.co.uk and use the username.plus.com version, but I can't work out how to do it on my mail account.  There is no mention of a globalnet domain anywhere, so I don't know my aliases from my redirects!