They can fire you if you don't come in to work when they tell you to.

You can refuse to work and your employer could fire you because of it.

No you will not be penalized you will be fired. They cannot "force" you to work but there is nothing to force them to keep you on the payroll.

Just go to work problem solved

No one can force you to work. You may get fired, though.

They can't force you to work.

They can penalize you for not working, like reducing your hours or firing you.