In the U.S., insurance is regulated by the states and each state has a regulatory agency where one can go with complaints about insurance companies. I find it surprising that the abused customer in this story didn't file a complaint with the government. That would have probably made the insurance company stand up and take notice much more than complaining about them on Twitter.
I never knew this, and sincerely doubt most people do. But besides this rare start-up, if you're an established player like Blue Cross, does one or dozens or even hundreds of complaints even matter?