Does the IRS have a legitimate branch for claiming money owed on parking tickets/?

I recieved a parking ticket in Multonomah county, OR. back in February. I forgot about the ticket after awhile until I received a letter, supposedly from the IRS "other agency" or something like that saying that I now owed over $120 dollars for the original $60.00 dollar ticket, and that if I did not pay it within 30 days I risked losing my license. So, I called the number on the paper, and set up a payment plan with a gentleman on the phone. When it came time to make the next payment, I realized I had lost the number, so I called the regular IRS number, and found no link to the IRS "other agency" number, and also found no listing online. I got the number once again from the courthouse, and made another payment. I realized that I was talking to the same exact guy that helped me the month before. A bit strange huh? The next time after that I searched for the number I was unable to find anything again, nor could I get ahold of the same department at the Multonomah County Courthouse. Because of this, I have missed several payments. I can pay it off entirely now, but I am starting to question the legitimacy of this "other agency" of the IRS. Does anyone know anything about this? Between talking to the same guy twice, only one person at the courthouse knowing about it, and the fact I have not received any more notifications, it seems a little fishy.