Call Payment processors and take as much time as possible (This is the solution).
The reason phone call complaints are effective with these payment processor companies is because it takes up valuable time that the company could be otherwise dealing with other issues. Phone support is expensive and slow, which makes it an ideal pressure point A large public outcry is what causes companies to pay attention and consider backtracking.
Make a script about why this is bad (payment processor companies shouldn't be censoring legal material because they personally think it's immoral and it's an attack on free speech - you can ask AI to create a script for you if you don't have to time to write a long message) then call VISA/MasterCard/STRIPE/Paypal, you'll be on hold for a while because everyone is calling, and say you'd like to lodge a complaint. Then when they ask what this is in regards to, just start reading your script. The longer the better since that's the point. We essentially have to keep this up for the next few weeks if we want something to happen. We don’t need to be aggressive - just persistent. Keep the pressure on and call every few days, or every day if you care about this issue.
The following link has all the contact information you need to call them:
Service reps will now try to quickly escort you to "e-mailing" instead once they realize you're complaining about itch and Steam's recent censorship - try to just keep them on the line. In one call when they attempted to do this, I simply asked, "Are phone call complaints reported to your company or not?" and they just kept repeating "You must e-mail _________" - I was like, "You're not answering my questions, do you report them or not?" and eventually they transferred me to a supervisor who was really awesome to talk to and spent a long time talking to me.. Asking them about why companies are attempting to ban legal content is also a good question that they can't answer but will keep them on the line for a while.