My kids teacher put her hands on my kid what do I do

My son was walking into the school and the teacher pushed him out the school and said it's to early to come in but my son has an i.e.p. he can't go in by himself he must be supervised at all times....i witnessed it and when into the school and told the teacher not to ever put her hands on my kids or any kid school called the cops and said I hit the teacher so I told the cop to look at the cameras tell see I didn't put my hands on her....