If they give you cause for argument– stay calm, state your points, and be ready to walk away!
You can choose to never use a certain bridge again.
“But I brought all the people myself, I already know them,” they would say.
Well maybe you could make up some professional looking flyers, pass them out, and get people you don’t know to come on out.
“But you are only paying me $75, How can I afford to make up flyers?