Parking inspectors, they're ruthless here. If your wheel is on the line, they'll stick a ticket on your windscreen. I parked outside my flat last night not realising they plonked a 'suspended parking' sign up (I wouldn't be surprised if it went up this morning). What did they charge me to collect it from up the road? £260 plus daily fees until I collect. fml.
Did they give you any warning as a resident that they were implimenting the change? Maybe they should have, worth looking into.