You are not gonna get a bill. You have to go into the site and get the bill. Log in and there is an option - somewhere - to get your bill. Print it out and mail it in.
Truth spoken there. I have never paid (never knew how, never asked) and just got off the phone with them after getting a super secret secure email. I am surprised they let it go this long. She said I was 120 days back, but it has to be more like 600 or 700. I am putting a check for $200 in the mail to them today.