We were paying for an unlimited connection, and then they tried to tell us that if we wanted to be connected for more than 4 hours/day, we'd have to upgrade to a business account that was like 4x the price. My dad told them to pound sand and we switched ISPs.
Pretty sure between 1995 and 1997, we switched dialup ISPs like 4 times because each tried to tell us we were abusing the "unlimited" access. And then at some point, cable modems came out and the entire thing became moot.