Sue for defamation and lost earnings, make them hurt financially. Witch mobs are illegal.
You don’t have to prove they really didn’t believe it, just that they didn’t care about the truth.
Malicious gossip is illegal, make the trial public and don’t settle out of court.
Demand your pound of flesh.
That is how defamation law is structured.
It’s a white sport and art form.
That means they make the rules and can exclude whoever they please. Like a pub or a club.