IMO, this thread is more complex than it might appear on the surface.
OP, going back to the start, an appeal was submitted against a NTD served on the vehicle and subsequently rejected. The rejection states that unless payment is made or an appeal lodged with POPLA, APCOA reserve the right to implement debt recovery procedures.
Subsequently a Notice to Keeper was issued under PoFA. A NTK is not 'debt recovery'.
This is procedural nonsense.
PoFA can only be engaged if the creditor does NOT know the driver's details.
If the initial 'appeal' against the NTD gave the driver's details (whether by accident or design) then there was no power to issue a NTK. And if the appeal didn't reveal the driver, then APCOA could only pursue the charge from the keeper after issuing a NTK...but the 'debt management letter is address to the OP's mother!!
OP, can we please see the original appeal sent in Sept. (you say this was posted by your mother who was the passenger and patient. Subsequently, you posted that the NTK was addressed to you)
And forget about the contravention, we need to sort out who's who and what procedures have and have not been followed.
And pl stop referring to 'we' and 'our', notices and letters are addressed to individuals so 'the passenger', 'the driver', the 'keeper' pl.