City of Chicago Department of Revenue Collection for camera enforced violations Chicago, Illinois

I got caught ticketed for running a red light on camera. I was going to fight it and made a date to do so. about the day of my date I figured it was easier to pay the $100. I sent them the check and they cashed it.
Almost four week later I get a collection notice for $200. I send them a copy of the cancelled check and a note. They respond and tell me this is for another ticket at the same intersection the morning after the first ticket. I was'nt even in Chicago at 5 am that day. I think they used the same picture and falsely created another ticket. This is the one for $200. I finally got through to them, and explaned this in a nice way. I finnally talked to a female superviser, and she agrees to drop the 100 dollar late fee. What has just happened is I agreed to send them $100 for a ticket I got and I was'nt even in the city of Chicago that day. On both days the times are all wrong also.
Their collection notice is loaded with all kinds of finacial theats. Should I pay this ticket, or fight it. They will not even give me a review  at one of their hearing because it has been to long. I did miss a review on one off the tickets because I sent them $100 for the first violation. I did not even know there was a second ticket. There is some real fraud going on here. What should I do? They will not meet with me.