I got an AdelphiaGRAM:
ALL YOUR CABLE TELEVISION SERVICES WILL BE DISCONNECTED ON OR AFTER THU MAY 13, 2004. TO PREVENT DISCONNECTION, IMMEDIATE PAYMENT IN THE AMOUNT OF -2.59 MUST BE PAID AT YOUR LOCAL OFFICE BY WED MAY 12, 2004.
After calling Adelphia, I found out that I didn't have to go visit them and pay $-2.59. You'd have thought that their automated billing system wouldn't send out bills to people who were owed money.