Possibly the reg was input incorrectly, as it says 'no valid session' - is the exit barrier controlled? You can appeal, they will reject it - if they see a very similar reg at the appropriate time they may offer the £20 keying error charge. They are with POPLA, so you might have more luck there. If not it will end up in a court claim which can almost certainly be defended - there is no invitation to pay or name the driver, nor identification of the creditor, so it is not fully POFA compliant.