E-470 Public Highway Authority License Plate Toll Sent a bill for $8.79 Denver Colorado

I received a one time bill saying it is late. I live in Michigan and have never been to Colorado. This company also sent attachments with a threatening tone. I googled them and apparently they have done this before. Some people same they are scamming the public. I realize they are indeed a real company. One person said they had an old license plate number on their bill. It was mentioned they reassign old plate numbers. They didn't list a license plate number for me, however I did have an old license number about 8 or 9 years ago. Could this be it or was i just randomly picked here in Michigan? I am 62 years old and disabled. This is an aggravation I don't need. Can you help?