It happened around 8 years ago ( in Italy fyi ).
I was hired at this small company where all the employees were young and easily influenced.
We were constantly remainded that there weren't other jobs available and to be grateful to work for them.
I was hired as a part-timer, but forced to work the full day as the other employees without over time.
( Even the other employees over time wasn't paid ).
When I received my first paycheck, I noticed that I was paid as a full timer.
I did not informed my manager or boss about that mistake.
A couple of months later one of my coworker found out about my wage and he went to complain to the manager.
Instead of asking for a better salary for himself, he complained that it wasn't right that my salary was the same as his…
They forced me to sign the resignation and re-hired me with the correct contract, but I was still due to work as a full timer.
I stayed there two more years ( almost all of my coworkers quit during that period ).
( Sorry in advance for any mistake, english is not my first language)