Ok - you should appeal the decision.
It may be that you had to register your vehicle.
But if you did not comply with the terms of the car park, then the fine is payable.
But you can appeal.
If they reject it, you can go to the independent body (if they are a member).
They offer a free, independent service and can consider your complaint for free at:
If they do not uphold it, then you can still refuse to pay.
They can take the matter to Court and you can explain the position to a Judge.
But try appealing first. However, you need to make sure you didnt have to register your car first.
Can I clarify anything for you about this today please?
If not I would appreciate a 5 star rating for my answer, the button should be at the top of the screen. If you need more help, you can ask follow up questions for free and I would be delighted to assist. Thanks!