Nick wrote:
In principle I've been agreeing with the congestion charge, but that
was until I was caught in this trap. On an evening and outside zone
hours I would like to drive to my g/f's flat that's inside the zone by
about 100 yards drive. In the morning I would leave the private car
park, enter the zone to drive 30 seconds or even less on a deserted
side street to reach the zone exit

This is not a "trap". You are driving on a public road inside the zone
during the hours of operation. Pay up and stop whingeing. If you don't
like it, get up earlier in the morning or use public transport.
--
Richard J.
(to e-mail me, swap uk and yon in address)