Also talk with the school counselor. He may be able to observe in the classroom and give you an objective opinion of what is going on there. The counselor may also be able to talk with your daughter and the other children who are upset and help them feel better about going to school.
If the situation does not improve, talk with the principal. Most principals do not like to move children to another classroom once school has started. Kindergartners especially get attached to their teachers and classmates very quickly, and changes are difficult for them. Ask the principal to work with your daughter's teacher to improve the situation in the classroom, and to move your daughter to another class if that is not possible.