Making money off highways as a main source of income

About a month ago I had a business trip to Austin, TX. While there, I decided to visit a neighboring city of College Station for personal reasons. Unfortunately, instead of listening to the locals I decided to follow the guidance of my trusty (if slightly dimwitted) GPS. Instead of taking highways 290-21, I took 79. Big mistake! The police was behind every bush (no pun intended) in every little town along the way, stopping people for 1 mile over the limit! They got me twice - one in the great city of Thorndale (for 64 in 45 miles zone at midnight). They even have a stationary radar there and the policeman gives you a nice price list, telling you how much you need to pay for what violation. Needless to say, that got me pissed so I decided to find a local lawyer and fight the ticket. According to the price list my violation is worth $190, so I decided I could afford another $100, but make things a bit easier for the next unfortunate soul driving though that speed trap and maybe give a hint to the town government that they should look for another source of income. I called several (3) local lawyers. 2 didn't get back to me, while the secretary of the last one nicely explained that they have more than enough work as it is and can not help me. Looks like just about everyone in that town shares of the profits somehow.
Well, having no options I decided to pay the fee. Obviously, they don't take checks, just money/postal orders. Sent them one over certified mail. I thought that to be the end of the story and the glorious city of Thorndale, TX and peculiar habits of its citizens started to fade from my memory. Apparently, that was too easy.
These guys now claim they haven't received the pledge and the postal order and threaten me with a warrant. What makes it strange is that USPS is sure they delivered the letter (one can track certified mail). Now I just need to see if somebody cashed the postal order. I wonder if this is how they double the loot - claim they haven't received it and make you send the money again?