B.
Parents should not have to beg for a conference to discuss their child. I am also a teacher and communication between school and home is very important. However, when it is only one sided, you do need to move past the teacher. I would pass on emailing the teacher anymore. At this point, you should contact the principal again. I would CC the teacher. A parent/teacher/principal conference is necessary and these issues need to be addressed. Keep records of the emails and any phone calls made to the school. This will only make your case stronger.
If you are not satisfied with the results of the conference, or the meeting does not transpire in a reasonable time frame, make an appointment with the superintendent. I would advise you to go through the chain of command first and let the principal know that you are not satisfied with the way things have been handled. Changes will happen, but you do need to allow the principal another chance to help you. Again, if you feel that the principal is nonresponsive, go directly to the superintendent and then the school board.
I wish more parents were proactive about their children. Best of luck.