Yes i understand what you want to achieve.
Just another example for your → BANNED ← function…
Wix calls it → BLOCKED <— instead of banned! How does it work?
Take a look here…(a simple example to demonstrate you a similar functionality)…
https://russian-dima.wixsite.com/login-system/vnloginmgm
- Login with the predefined ACCOUNT → mr@president.com (PW:12345)
- Navigate to → CONTACTS
You will find an overview over all of the existing/registered CONTACTS/MEMBERS/USERS on the site.
-
As you can see → the second CONTACT on the screenshot is → BLOCKED <–!
It is the teacher@test.com-Account (PW: 12345). -
Now log out again and try to log-in as — > teacher@test.com! What happens?
-
So it is a very similar functionality to your wished function.
If you take a closer look onto the whole Login-Management-System, you will surely find even more similar functions, also ones, which are planed to be developed soon, for example…
Oh yes → it will also include a → NOTIFICATION-SYSTEM !
A user will be informed almost the same way, you are expecting 
.
You can inspect all the shown example, perhaps it will help you to generate your own System.