How to permanently delete notifications?!

Hello,

I'm getting super frustrated with 'Notifications'. I wish there was a way to turn them all off completely and delete that part of Mac OS. I'm running 10.13.3. When I go into the Notification Center settings, I get the list of all the apps that send me notifications. I understand I can go in and for the 'style' select "None". Then uncheck "Show notifications on lock screen" and also uncheck "Show in Notification Center".

But what about DELETING the website all together from the list? For example, in the list, there's "Mail", "Maps", "Messages", "iTunes", etc.. One of the one's I don't want is from a third party website (Mac Rumors). If I highlight any of those and delete it, it goes away in the window. But when I close the window and re-open settings, it's back but this time, it's set to show "Banners" and other notifications!

How do I make it go away forever?!?!?!

Any help would be appreciated.