I have an idea, though I can't gauge how helpful it would be.

Issue a rating of Square Enix to the Better Buisness Bureau, documenting their performance in upholding the standards of their own Terms of Service, End User Lisence Agreement, whatever.

Square Enix has no obligation to adhere to, or seek approval of the BBB, but the BBB is scrutinized by journalists, and a spike in negative opinions on a topic for a business would get eaten up by some of those journalists. The overall goal here being to instigate negative publicity. This ended working in the case of Destiny 2 by Bungie, though I can't promise Square Enix would care.