They nominally don't do just anything (like take your money), because they want people to use their service, and if they cheated everyone all the time, you'd hope that people would catch on and stop using their service.
Having said all that, dealing with illegal transactions, fraud and scammers is tough. The corporations will, honestly, make mistakes, and having enough customer service to deal with it all properly is expensive. Hence automated bans. Often there is no recourse except moving towards a lawsuit, which may be unreasonably expensive for most cases, as compared to the money that has been lost.
I'd guess that they'd just not show up, you'd get a judgement, and then just have to figure out how to get it paid. Or maybe they will show up, hire a local lawyer to represent them and point out the fine print in the ToS that forbids holding them accountable for any reason in any venue. And with any luck, the judge will laugh at them and give you treble damages.
Problem is, it's not worth whatever court costs I would probably incur. Granted, there isn't a lawyer involved in small claims, but could they judge order me pay their lawyer fees if I lose?
[0] https://www.federalreserve.gov/paymentsystems/fednow_about.h...