could just be a glitch in their billing program. go talk to them. if indeed you have to pay work out a plan..even if you pay $10/month they can't do anything about it....if that is what you can afford....it might be something as simple as you need to resign a form or something. sometimes policies change and things get caught in the middle.

if ect is working don't stop it, just go to the business office and talk with them. if after all these years you just got this one rogue bill to me it seems like a mistake or policy change. but like I said if all you can pay/month is something tiny, they can't really do anything about it. pay it off even if it takes a million years....trust me, been doing that with mine.