they died
Slaves who refused to eat could be subjected to physical punishment such as whipping, beating, or being force-fed. In some cases, they may also be confined in small spaces or deprived of food as a form of punishment.
Hermione refused to eat the feast once she learned that the house-elves who made the feast were slaves.
slaves either refused to work for their masters, or they may work less efficiently.
They happened, because the south was afraid of an uprising from the runaway slaves joining with the Seminoles, and because the Seminoles refused to move off their land.
Many slaves slowed down their work or refused to work at all.
If slaves refused to do work, they could face punishment, such as physical abuse, imprisonment, or even death. Slaves were often threatened or subjected to harsh consequences to ensure compliance with their owners' demands.
people had less slaves
When a man and a woman slave got married they were expected to have a child in at least a year or so otherwise the couple would be separated.
i want to now what happened
Yes, of course. However, slaves probably did not eat as well as their owners.
they rot