Welcome, Vicky.
You've had a lot of good advice. I know it sometimes seems overwhelming, but when you grab the reins of control back from the chaos this school seems to be generating, you will feel less overwhelmed. You have rights. Your son has rights. Sounds like these are being violated.
I especially draw your attention to Beth's suggestion that you keep a diary - this helped us immensely. Far more than we would have thought. What we did:
We got an ordinary school work book from the supermarket and put a plastic cover on it. We labelled it "difficult child 3 - Communication Book" and put a sub-label which said, "Friends, teachers, anybody - this book is to record anything different, unusual or relevant that we need to communicate between each other about difficult child 3. Please use it freely."
At home we would write in the book if there had been a problem through the night, or if difficult child 3 seemed a bit more distracted than usual. It was a sort of "heads up" to the teacher. For example - "difficult child 3 had trouble sleeping last night and is likely to be more tired than usual today." With this information, the teacher and the aide are both equipped with something extra to help them understand difficult child 3 for that day. And they may write, "Thanks for the warning. Yes, he was a bit difficult this morning but once we started on maths he settled right down and worked well. Things went badly in the playground though. He simply doesn't know how to join in, the social problems are still quite a problem. How about we ask the school counsellor's advice?"
This book replaced the frequent conferences on the classroom steps, as well as put it all in writing. The book contents were not intended as a legal record - far from it (although in our case it actually happened that way at one point). But it meant that after a day teaching our son, the teacher did not have to add a talk with us to her litany of woes. Instead, she could head home all the sooner for a restorative G & T.
We could read through the book and see patterns emerging that we wouldn't have noticed so readily, just seeing what we saw at home. Ditto for the school. There were many times when (via the book) we put our heads together to try to sort out problems.
The school wasn't perfect, by any means. I also never used the contents of the book against anybody who had written in the book. However, it came in handy when I was accused by SD of being on school premises without permission and I could point to the book as proof that I DID have permission, in writing. In fact, my presence had been requested. And when SD tried to say there had been a miscommunication - the book proved that there had not been, and that any miscommunication was neither the school's fault, nor the family's.
But the main aim of the book is to dramatically improve communication between home and school. It also helps the school staff to have an opportunity to vent. If a teacher wrote, "difficult child 3 was a little horror today, you're welcome to him for the weekend," I might reply with, "Thanks! At least it's only two days, you've got him for five next week," as part of a flippant reply.
It is also important to include good stuff in the book and not have it as purely a litany of woes and faults. "He didn't have a good morning today, but I could see he was really trying to hold it together. He's difficult but at least he wants to be good."
That is the Communication Book, in a nutshell (OK, a big nutshell). When a teacher one year tried to phase it out because she felt it wasn't needed, she cracked under the pressure. We reinstated the book and things improved within a week. Even I was surprised by what an amazing difference it made.
Others here have urged you to put your concerns and complaints in writing to the principal - I heartily endorse that, as well. As soon as you begin to leave a paper trail, they begin to treat you with more caution and to not try to bend the rules. A phase you may find you need to add - "I require a response in writing..." because in all the letters I wrote, I NEVER got a reply in writing.
Another recommendation, especially if you're not getting written replies - make your phone calls with a sheet of paper and pencil with you,and then transcribe it to the computer. Minute all your phone calls to and from the school. List date, who you spoke to and what they said. If you can remember what they said word for word, put it in quote marks. If, in six months' time you have cause to quote those words back at them, it really scares them (in a good way).
An even better proposition is to make your calls while you're on the computer with the diary file open so you can type directly as you talk. If they can hear the sound of the typing - so much the better.
If they realise you're no longer letting them make the rules without checking up, they will clean up their act smartly and things should improve before you even need to lift a finger. And if/when you do need to get heavy - you have all your data already on file.
Keep all originals, make sure all reports are copied to you and copy the copies rather than take your only copy to appointments, etc. It's a housekeeping paperwork thing. There's nothing worse than trying to find a vital piece of paper, only to remember you loaned it to the pediatrician or the school counsellor. I loaned videotapes to the class teacher and have never got them back. Very annoying - I had compiled every TV program on autism into one video and I didn't copy it first before I lent it. I suspect the teacher never bothered to watch it anyway.
Good luck with this one. You're about to have to become very expert in Special Education rules.
Also, I'm amazed - nobody yet has suggested you grab a copy of "The Explosive Child" by Ross Greene. With everything else you may not have time just yet, but at least make time to go to Early Childhood forum and look at the discussion there on this book. Even if the diagnosis is still being queried, this book can make a big difference to you and the school. It might also help you pinpoint why you don't like the Special Education teacher. You may have a good reason, or you may have misjudged her. The book may help you see more clearly.
Good luck. Keep us posted.
Marg