why didn't they revolt if their life was hard?
Why didn't they revolt? Well its because they were weak and have no educations. With lack of education, they were not able to plan any escape. Why didn't they get any education, well its because of their master. Their owner/master knew if they had any education, they would be able to revolt or kill the master them self. So the owners forbid them from getting Education.
All the slaves know was to work hard.