Earlier quoted context omitted.
Are you familiar with the freelancers' concept of "fuck you, pay me"? I guess, that's how the first part works. There are things you can try, and there are other things. Messing with freelance pen testers is clearly one of latter.
The freelancers „fuck you, pay me“ is based on very clear contracts and respectful communication, even when things go bad. This is not what’s happening here AFAICS.
Once they have shadowbanned the author, IMO, any attempt at respectfulness is violated by bug bounty organizers.
Maybe there are things more rude than shadowban, but I'm not aware of such.