> Working beyond 10 hours on a day requires authorization and is extra paid.
> Working over weekends requires special approvals and is properly compensated.
I'm amazed that you believe you require a union to ensure proper compensation in a country like Germany?
Is it because you're a contractor rather than an employee or some similar sillyness?
Why isn't being paid for your time the default?
http://www.equaltimes.org/exploitation-of-migrant-workers?la...
https://www.thelocal.de/20150602/eu-reports-widespread-abuse...
Surely they're not required to get an employer to follow the law. Isn't there a better way?
Sadly not that I am aware of.
Either you go alone with a lawyer, or get some muscle beyond you.
For example, even for simple matters like vacations, many people are actually unaware what are their rights, benefits, obligations and how much control the employer has over them.
Many just take the simple route and believe whatever their boss tells them, instead of checking what the law actually says.