Are you possibly trying to use the app? They are generally all on free vend at the moment and work without the use of the app to get them started.
Despite their age and reputation, their CCS chargers have been faultless for me for a long time now. Though as you mau have heard, the Electric Highway is now under the control of Gridserve. Over the next few months you'll be seeing all of the existing chargers replaced with brand new units operated by Gridserve, rather than Ecotricity. Only two locations around the UK have them at present, but this will all change soon.