Hi B.,
I'm so sorry you've had this experience. It does sound like something that would shock me also, especially from the director of the preschool. Like others, I feel that since this preschool is a private one, you may not have much recourse unless they accept state funds.
Private schools sometimes have their own 'board' and the board approves policies about acceptance and about dismissal from the school. Did the director share anything like that with you? I'm wondering if they followed their own policy. I certainly hope your years tuition was refunded if you had to pay ahead. Their school is expensive and I can't imagine paying twice!
I hope your son's new preschool is wonderful, that the teacher is amazing and that he loves every minute!
I have three grown children; 20, 23 and 25. I work in the education department in San Jose at Parents Helping Parents.
Our agency gets a lot of calls from parents whose children have been 'dismissed' from private preschools and private schools as well. It happens more than you would think.
Take good care and help your son view it in a positive light. Sometimes schools are like trying on clothes; you have to find the right 'fit'. L.