Dealing with race directors: Many of them these days are business people who know nothing of running, it is just a monetary opportunity. They are not running the race for the winners or even real runners. They are running it for the masses of joggers / walkers. There are 100 of those people for every competitive runner, so we don't matter to them.
There is only one thing they will understand. Money. If you paid by check, cancel it. Stop going to their race. But you are not enough. Tell everyone you know and Flame them on social media and any other review site you can find. But be sure to make it sound like they did wrong for everybody by focusing on things like lack of port-o-potties, not enough or crappy finisher medals, mis-marked course that made many people run extra distance (joggers / walker really don't want extra distance). A road that is not closed and uncontrolled intersections are dangerous for everyone, so focus on that.
In reality, you will get no recognition or apology for your race. It is ruined for you. But you should definitely try to ruin the race financially for next time.
Good luck.