They are paying me 6€/h, to develop in fucking FoxPro, as a freelancer, illegally.
I don't know how to tell them I'd make way more money as a dogsitter (and also enjoy it way more).

It all began as a favor for my old company, "we really need it plz plz" and then I became a slave.

Stop hitting yourself

@electrineer they paid me 320€ for 3 months of work overnight

Just quit?

@Manuch did they put a gun on your head?

Yeah I quit the job, I told them this morning I was very pleased to work with them, but dogsitting seems way healthier
He actually told me he is going to ask in and look for a solution (I spoke with the analyst I work with)

"I don't know how to tell them I'd make way more money as a dogsitter (and also enjoy it way more)." - then why don't you do that instead?

@tosensei I did that this morning xD in a kind way, but the message went through
They told me they spoke to the manager, meanwhile they told me to start asap the next work because the customer is in an hurry. Now I gotta trust them, I guess

@Manuch i meant: why don't you walk dogs? ;)

also: don't trust companies. they're not your friends. they're moneys friends.

Honestly, you are agreeing to do things on terms that you don't want and that's your own fault. If your old company wants these things doing, so they can get paid, that's their problem. It isn't your problem. You have a niche skill that is in demand and of value right now, but will likely not always be. If this is as good as it gets, why are you doing it at all?
This company could very easily send you a better offer, in writing, before you get started. If you want to tell yourself there's no time for that and you've got to work for peanuts again, they aren't going to tell you any different.

ah the "favor" lesson we all must learn. i too learned the hard ways of the "favor"

don't be an idiot. you're fucking yourself and the industry.

@Manuch "Now I gotta trust them it seems"

You see, that's how you got into this whole situation in the first place

That's the issue with bad price anchoring

I just asked for 20€/h and waiting for a response, a little less than a dogsitter.

What is illegal here in this case?