E470 Express Toll Express Toll Double Billing, Assessing Late Fees for toll charges that don't exist Denver, Colorado

When I moved to Denver, my wife and I had two cars with us which we registered with the toll road people so that we would be sure to get our toll bills promptly. Then we brought a third vehicle with us and forgot to notify them. So when I used this third vehicle on the toll road once, we got a bill that did not automatically debit from the account we had set up with the company. Okay, my mistake, so I called them to add the third vehicle to the account. Now everything should be okay, right? The tolls should debit from the $35 we paid them to fund our account. 

Today I got a threatening letter from some bullsh*t law firm that we owe $25 in late fees. I know that if I tried to fight it, it would turn into $50, then $100 and so on. So I paid it to make it go away. But then I thought, "What if I get this notice again? What if they didn't actually link the third car to the account and I don't know about it until late fees are assessed?"

Can't check my account on the website. Guess what - It's down. I did a little online research and have learned that they are notorious for ripping people off by not fixing their broken system. I think its time for a big a** class action lawsuit. Who's in?!