VFR

Yes that thought crossed my mind as well as this would be the first thing I would do.
Certainly pay to join the union as well, as managment are less inclined to upset union members.

manamama

Spainboy

If you don't get anywhere after speaking with the managers, it's time to get off.

A bit earlier than expected but sometimes you have to cut your losses etc.

Good luck.

Mitzyboy

I cant see why theres talk of denuncia and lawyers

If your pay packet is short at the end of the month you go to the accounts / admin office and tell them. then if they say, sorry its a mistake, they will presmably pay you. If they dont pay you, or they are dismissive, its at that point that you start talking legalities. Once you get to that point though, quite frankly, you're probably looking for a new job anyway!