Via their website, I notified EZPass that I left my tag in the car I traded in. They sent me a replacement tag (no letter or instructions attached). I mounted it. Two weeks later they sent me another tag (don't know why - no letter or instructions). I replaced the tag I previously mounted.
I have since received 12 violations from the earlier tag. Apparently it wasn't functional.
I should not be responsible for the earlier tag not registering. It was their error. The violations total $208. It's a unjust hardship for me to have to pay these fines.