I think my son's teacher may be a bully!

My son is in fourth grade.  He was in Head Start from the ages of three to five and then started grade school at age five.  He's been in trouble twice [this was last year] in all that time.  I've always been told that he's a good student and a happy child.  In fact, he won the "Quiet Leader Award".  So now he has a teacher that has him in tears at least two times a week.  If one child is acting wrong the entire class loses recesses for a WEEK!  He was sick last week and missed two days.  Well, even though he was sick we still needed food and I needed to get him medicine.  So I took him to the store.  Somehow the teacher found this out.  I wrote him a note to tell her why he was absent and she took the note and told him "You weren't sick, a little birdie told me you were out with your mommy."  She makes rude comments, keeps the kids after school [thus causing all the buses to be late] and punishes them in ways I think are wrong.  This week he misses all recesses because he didn't get his chair on top of the desk.  She said "I'm giving you a few seconds to get your chair on your desk or you miss recess."  This wasn't because he was goofing off or anything.  It was what she said to the whole class and it took him more than a "few seconds".  When I heard this from my son I walked back to the office to find her to sort this out and she was no where to be found.  I have asked her many times to either call or meet with me and she will not.  I've gone into the school office to talk about it and they say I must work it out with the teacher.  I can't do that if she won't let me!  I called the school district office and they said to work it out with the school!  Meanwhile my son is starting to hate school.

I am not a parent who thinks my child can do no wrong.  I just want to see what the problem is and I can't.  Any suggestions?