The fact that it's "free" parking is an even more compelling reason to challenge!
The reality is if they don't issue a ticket to the DRIVER at the time and default to using ANPR cameras, they can ONLY (because they cannot identify the driver) chase the Registered Keeper and invite them to:
1) Identify the driver
or
2) Pay the amount of the outstanding charge.
The RK is under no legal obligation to identify the driver and if they do invoke "Registered Keeper Liability" they HAVE to follow a very strict set of rules, which many fail to do. A simple mistake in procedure is enough to challenge and get the ticket cancelled.
I know, because I have done it...…….
But your car park entry time was 10:14 ?!
From which we can deduce the appointment lasted approx 40 mins data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 After which they moved to the retail park car park.
Think we should fine OP for banging on about it! data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
Well that didn't work I got a letter back saying they have reviewed it and I still have to pay, nothing saying about what I had asked for.
Respond, telling them under GDPR they are required by law to supply all images they have related to the vehicle of which you are the registered keeper and that you will not consider the payment of any outstanding amounts until they do. Remind them the clock is running and that if they fail to supply within the time period you will immediately report them do the ICO.
Hold your nerve and keep playing the game
They wouldn't have even read your letter. That would be their standard initial response to get people to pay.