Some DBTs seem to have problems reading the meters; it's in the operator's interest to get them fixed, especially if they charge per kilowatt, or count 0kWh as a failed charge and due to be refunded. What did your vehicle think was happening? Was electricity drawn?
And all the other services were rubbish in their own ways too:
Chievely - huge queue along the slow lane to get into the slip road.
Newbury - iced by a pickup with smashed tail lights, and an occupant smoking a *** in the front passenger seat - couldn't be bothered engaging with him to get access (and the charger usually fails anyway)
Leigh Delamere - AC charger out of action.
So had to depend on the rex and drive easy to get home without a petrol stop. It was a bit chilly.