I feel very worried for you as you are stuck in a situation which probably feels more helpless than it really is. Because you are not alone, you will be more inclined to think there's nothing you can do to change your situation (because it appears everyone is apathetic and/or have been reprimanded as an example).
When a person is stuck in an abusive work placement, he/she develops a thick skin to it - to the point where some negative situations don't seem as 'bad' as others. ("Oh they took away our chairs...? Well, at least they didn't shorten our unpaid lunch...")
Surely there's someone (an outsider) you know who could drop by to assess how bad things really are, and then act on it if there are negative situations. I realize there's no law against not providing an employee with a seat, but I am sure this company is not following through on some legitimate employer standards.
It's hard to 'prove' verbal harassment and/or threats but it's easy to have an outsider file complaints regarding the physical worksite.
Just google The Occupational Safety and Health Act and you can get any of your workplace questions answered. If you could get even three outsider 'friends' to literally file a complaint a week - eventually something would have to change.
Here's an example of a potential complaint:
"OSHA (the Occupational Safety and Health Act) contains regulations which require employers to provide at least one restroom for each 20 employees of the same gender. The provided restroom should include adequate hot/cold water, hand towels, and soap."
How does your work site measure up?