Posting seems to have brought some good luck. A dear friend was at the center last night and spoke with the instructor and the office manager and got the center's unofficial update on our situation.
It seems that the GM was appalled that the area supervisor (think minimum wage cashier) thought she had the authority to ban anyone from the facility. She was apparently reprimanded (unofficially??) for calling the police instead of the GM, for thinking she had any right to ban anyone from the facility, and for targeting my boys when even she admits there was a group of kids and no attempts were made to identify any of the others.
Supposedly the GM is working with their legal counsel to find out what hoops have to be jumped through to undo any police 'no trespass order' and to ensure that the police understand that only the GM has the authority to speak on behalf of the center. My friend reported that both the instructor and the office manager said that the GM thought my proposal was fair and that was what he was going with. They are also holding our families spots in the classes (despite having a waiting list) pending getting all this cleared up.
I'll still worry until I officially hear from the GM, but at least now I have hope.
