I parked in a pay-and-display area at 17:05. Put £1 in the machine (charge
is £1/hr) and the ticket came out valid until 17:30 after which time parking
is free. The signage also confirmed that parking is chargeable only between
09:00 - 17:30.

Came back to find a parking ticket, time-stamped at 17:36.

Clearly the parking attendant was trying it on, aware that a certain
percentage probably just pay up. But I want to make a stand and sue the
council for wasting my time. Would I be reasonable in charging a £50 admin
charge for having to issue an explanatory note..?

Cheers