You are dealing with an unregulated private parking company formed by a bunch of ex-clamper scammers who rely on low hanging fruit on the gullible tree for their income. The decision whether to pay or to fight is down to you.
You now have an opportunity to appeal to POPLA. Even if you lose at POPLA, the fight is not necessarily over. A POPLA decision is not binding and has no bearing on a Plan D court hearing where a judge would ultimately decide whether you owe CEL a debt or not.
Did they offer you the
bribe discounted sum when they rejected your Plan B appeal? Offering to pay them £57 will not be accepted by them.
Here are a few suggestions that should be included in your POPLA appeal if you decide to fight this:
Your POPLA appeal will focus on issues with the signage. It is apparent from your original post that you were not made aware of the terms of parking due to deficiencies with the signage. You will put CEL to strict proof that any signs were prominent, conspicuous, written in intelligible language, easy to read, see and understand. There must be adequate notice of the sum charged and that it was brought to the attention of the driver as required by PoFA. In this case the sum of the charge is in a much smaller font to the information that precedes it. (on a sign that you did not notice until later)
You said that when entering the location, on one side is free parking and on the other it is controlled by CEL. You need to put CEL to strict proof that the signage on entry complies to the BPA CoP and that it is not possible to mistakenly park where you did, only realising later that you were in the controlled side of the car park.
Their use of ANPR is hidden in the small print of the sign you showed us. It is not transparent. They should have conspicuous notification, preferably by use of a logo and prominent wording that ANPR technology is in use as per the Surveillance Camera Commissioner’s Code of Practice. Also, the ICO has guidelines on ANPR use that states that there must be "clear and prominent signage in place to inform individuals that ANPR is in use, with sufficient detail about who to contact if they have a query". The sign we have seen fails that requirement.
BPA CoP v8 S22.1 (at time of event) "You may use ANPR camera technology to manage, control and enforce parking in private car parks, as long as you do this in a reasonable,
consistent and transparent manner. Your signs at the car park must tell drivers that you are using this technology and what you will use the data captured by ANPR cameras for".
https://www.britishparking.co.uk/write/Documents/AOS/AOS_Code_of_Practice_January_2020_v8(2).pdfhttps://www.britishparking.co.uk/write/Documents/AOS/NEW%20Redesigned%20Documents/Version91.2.2024.pdfYou will put CEL to strict proof, if they are not the landowner, to provide evidence of an unredacted contract with or flowing from the landowner that clearly indicates the land enforcement boundary they are authorised to operate. Also, you require CEL to provide evidence that the landowner authorises them to issue parking charges in their own name.
It cannot be assumed, just because CEL is contracted to merely put some signs up and issue Parking Charge Notices, that they are authorised to make contracts with all or any category of visiting drivers and/or to enforce the charge in their own name (legal action regarding land use disputes generally being a matter for a landowner only).
Witness statements are not sound evidence of the above, often being pre-signed, generic documents not even identifying the issue in hand or even the site rules. A witness statement might in some cases be accepted by POPLA but in this case you should suggest it is unlikely to sufficiently evidence the definition of the services provided by each party to the agreement.
Edited to add: Are the images in the NtK time stamped? It is difficult to see. If they are not, then there is an extra point you can use in your POPLA appeal.