How Do You Stop a Customer From Guilting You Into Free Stuff?
People test boundaries because testing costs them nothing and pays off big if it works, that's just incentive design. They push because of: 1) the foot in the door technique, a small ask makes the next ask feel reasonable 2) reciprocity norm exploitation, they act wronged so you feel obligated to make it right 3) loss aversion, they'd rather manufacture a complaint than risk not getting something for free. Give in once and you just trained them exactly how to work you.
How the game plays out
Customer complains about something minor
You comp it to end the awkwardness
They remember, they come back for more
Now every visit starts with a demand
How the ask escalates
Nobody's ever tallied whether that free refill costs more than the bad review it prevented.