Ask HN: How do you fight unjust bans from online platforms?

Many people have become reliant on platforms like AirBnB, Paypal, and Facebook to the extent that losing access would have a significant adverse impact on their lives or livelihoods. At the same time, many of these platforms are well known for suspending or banning unsuspecting users without providing information about their reasons for doing so, and without providing any clear path to appeal or escalate.

Faced with such a suspension or ban, what approaches are most likely to be effective in getting it reversed? Are there actions one can take that most users might be unaware of?