There's little you can do, and it sounds like it was a shitty job. Anything you'd recover in a lawsuit (and winning one against them is a long-shot) is going to be based on the income lost from that job, and wouldn't be worth it. If you were a salaried employee, you might be able to push for a severance (maybe a month?) on account of the circumstances your departure making them look bad, giving them an incentive to settle. As a temporary hourly worker, I don't think you have that credibility, and I think they can fire you pretty much at will: your services aren't needed. A termination suit would be unlikely to win you anything, and the reputation effect would cancel out what you're likely to win.
If Juno Pacific harmed your reputation at Kelly Services, you might have a claim of tortious interference. But, unless otherwise specified, JP has the right to cut your hours to zero, which means terminating you.
It's going to be a he-said/she-said battle, but the truth is this: you made the executives look cheap and stupid (because they are) and they canned you as a "troublemaker". It's a tough call what is legal in dealing with "troublemakers". Attempting to unionize (which is not really what you tried to do) is protected and not fireable. Making executives look bad (which you did) is "insubordination" and fireable. Where's the line between "a troublemaker" and "insubordination"? Judgment call, very subjective. Is it right, what happened to you? No, but that's how the system works right now.
Corporate survival protip: rabblerousing is rarely worth it. I know, from experience. If you don't care enough to start a union (and that's a ton of work) then you should just do your job and keep those sorts of opinions to yourself. Shitty companies are like Wrongness on the Internet. If you fight them all, you'll never get anything else done.
TL;DR: they probably didn't break the law, you almost certainly won't get anything even if they did, and your best course of action is just to get another (better) job.
There's little you can do, and it sounds like it was a shitty job. Anything you'd recover in a lawsuit (and winning one against them is a long-shot) is going to be based on the income lost from that job, and wouldn't be worth it. If you were a salaried employee, you might be able to push for a severance (maybe a month?) on account of the circumstances your departure making them look bad, giving them an incentive to settle. As a temporary hourly worker, I don't think you have that credibility, and I think they can fire you pretty much at will: your services aren't needed. A termination suit would be unlikely to win you anything, and the reputation effect would cancel out what you're likely to win.
If Juno Pacific harmed your reputation at Kelly Services, you might have a claim of tortious interference. But, unless otherwise specified, JP has the right to cut your hours to zero, which means terminating you.
It's going to be a he-said/she-said battle, but the truth is this: you made the executives look cheap and stupid (because they are) and they canned you as a "troublemaker". It's a tough call what is legal in dealing with "troublemakers". Attempting to unionize (which is not really what you tried to do) is protected and not fireable. Making executives look bad (which you did) is "insubordination" and fireable. Where's the line between "a troublemaker" and "insubordination"? Judgment call, very subjective. Is it right, what happened to you? No, but that's how the system works right now.
Corporate survival protip: rabblerousing is rarely worth it. I know, from experience. If you don't care enough to start a union (and that's a ton of work) then you should just do your job and keep those sorts of opinions to yourself. Shitty companies are like Wrongness on the Internet. If you fight them all, you'll never get anything else done.
TL;DR: they probably didn't break the law, you almost certainly won't get anything even if they did, and your best course of action is just to get another (better) job.