Does having a "Wall of Shame" make sense? Basically put details on a shared google sheet with names, details etc., so that:
a. Other freelancers can avoid them.
b. They know about it...
"Wall Of Shame" solutions (i.e. reputation databases) mostly fail because they're easily subverted via poisoning/enshittification, unless they're curated, in which case the curator(s) may be subject to various forms of abuse.