It sounds like you did the right thing. In even good jobs there's a certain amount of shit you have to put up with to prove that you are a team player and are not just some entitled whiny bitch. It sounds like you've put in more than your fair share and then some. Meaning: at this point, the problem isn't you, it's them.
Kick back and have a drink for now with your head held high. You did what you could. You'll get to the next thing soon enough.
Secondly, tell them to quit too instead of being depressed, the job sounds like a complete and utter ripoff of a fraud. Never in my life did I think that kind of job conditions would be real in sizeable European country. You take what you can get when you are out of options, but even that should have its limits. Good on you to take the step, litterally anything you do after this should be better then a job that made you feel the way it did and was scamming you.
Yeah. The description of that job reminds me of those scams run here sometimes where you pay some agency for training and supplies so that you can profit from the sales, but that's just a scam for the host company to make money on training and supplies to keep you in terminal debt.
For all you know, the ownership/management at that place could be walking off with laptops and shortchanging your paychecks at the same time so that they can double-dip into fraud.
Got the lamb and chicken marinating in garlic, lemon, oregano, and other goodies. Lemon pastries made. Now time to spray down the screened-in porch and hit up Breaux winery.