I figured the courtesy notice was in error but it never hurts to ask. Now, you need to start considering where to go from here. Do you believe you properly stopped at the stop sign? If so, you have to decide if you want to fight the ticket. That will require being able to poke holes in the state's case against you, which is often an uphill climb, or playing procedural games in the hopes they mess up somewhere. If you know that you did what they are accusing you of, you have 2 options. You can pay the fine and see about taking traffic school to mask the point or you can fight the ticket in the sense that you make the state prove their case against you in court.
Heh, asked to pay 0$? You're a funny guy. What do you mean, "asked for arraignment"? Arraignments are usually walk-in court, typically in the morning. You pick any date before your due date... don't have to schedule or anything.
They seem to be a sloppy outfit, so they just may mess up in other ways too. I'd "play procedural games."