Freedom of speech vs disortly conduct ?

You do not have the right to cause a disturbance in a public place. You have the right to voice your opinions to the proper people, but you were not doing that. You were being rude and disruptive. You were wrong and could have been charged if you had not left. Next time make an appointment before going there and stay within the rules. You will get more people to listen when you do it the right way.