Ask HN: What is the best recourse when an account gets robo-banned?

This is a bit of a broad question, but I've run into it several times, so I'm curious how other HNers handle it.

The scenario is pretty simple:

You're using some mainstream service, let's say Facebook, Discord, Tinder, Gmail, PayPal, Amazon, etc. You're using it not by personal choice, because if you had a choice, being the HN reader you are, you'd probably use an open source and self hosted option. Rather, you're using it because you want to participate in mainstream society and engage with people on the platforms where they are.

To the best of your knowledge, you're sticking to the services' TOS and Code of Conduct. Maybe you're thinking outside the box a bit, because again, you are an HN reader, but for the most part you're a well behaved user acting in good faith.

Then one day it happens, you upload a photo, or withdraw some money, or join a server, or send a message, and suddenly, with no warning, you're locked out of your account. You get a message saying you've violated the terms of service and your account has been deactivated. There is no explanation, and no chance for appeal. You're locked out from doing whatever it was you were doing that you depended on the service for.

So, what do you do? Are there effective ways to get a response, or file an appeal, with these companies? Talking to many of their support teams is like talking to a brick wall. Are there secret ways to get through to someone with the ability to help? Are there legal actions you can take? Does publicly complaining about the issue with a blog post or on Twitter help, or is it a waste of time? Is it better to just cut your loses and move on? Stop dealing with the company altogether?