Long story short:
I work for a state agency in Brazil (like IRS). Pays very well and I've got some friends on the administration.
They asked me to do some work (beside my regular workload) for them and I accepted (huge mistake). Those tasks were supposed to be done outside my regular hours, without compensation. Just to help them.
For a while, they recognized me as a very good employee and offered me a supervisor position (pays a little more).
I accepted the offer and made a very solid work. The efficiency on my sector was up 500% and they kept offering me higher positions.
But my wife got pregnant and I was missing the free time that I had with her and my 3yo boy, so I asked them to step down to my last position.
They got really mad and burned me for “leaving them hanging”.
Not a simple thank you for all the help that I've gave them.
To this day, they see me as a bad worker because I'm not “aligned” to the management.