Get in touch with your state's ADA coordinator. There might be one as a part of the parks department or it might just be someone in the social services department. This is an issue they should be made aware of and your bringing it up could result in a better outcome for other families in the future.

Any state, city, etc. that gets federal money has to have an ADA coordinator and a complaint procedure.

Look around the agency websites and you'll probably find someone.