Lappy's Left 4 Dead 2 Dedicated Server.

Private Server for Custom Campaign in Hard 20[docs.google.com]

How to join
You can't. We're not accepting stangers. This server is only for private game. We do indeed play public on official campaign times to times but that's more for testing some new settings or warming up for our next custom campaign.

I got banned while you were playing public
If you got banned this isn't Lappy's problem. The Admins use their powers only when it's necessary so you probably deserved the ban. Usually, they are banning for: being a new player in a Expert Lobby, rush and die then instant rage quit, being afk every 2m, being toxic for no reason, spam vocalizer, join and try to team kill everyone.