The notice states that payment was not made for parking - did the driver pay? If not, why not? A good first step is usually to speak to the landowner to see if they will intervene, but we could do with knowing more about the incident in question first.
Can you confirm that you are the registered keeper of the vehicle in question (i.e. you have the car's V5C document in your name and address)?
Park With Ease don't appear to be seeking to hold the registered keeper liable, and have not complied with the conditions of Schedule 4 of the Protection of Freedoms Act 2012 (link in my signature) in order to do so.
Therefore, assuming are the registered keeper, you could appeal as the registered keeper (being careful to not reveal, via any tick boxes etc on the online form, who was driving), along the lines of the below:
Dear Sirs,
I have received your Parking Charge Notice (Ref: ________) for vehicle registration mark ____ ___, in which you allege that the driver has incurred a parking charge.
I am appealing this notice on the grounds that I have no liability for this matter as the registered keeper of the vehicle.
I note from your correspondence that you are not seeking to hold me liable as the registered keeper, under Schedule 4 of the Protection of Freedoms Act 2012 ("The Act"). You have chosen not to issue a Notice to Keeper in accordance with The Act, and it is now too late for you to do so.
There is no obligation for me to name the driver and I will not be doing so. As I have no liability for this charge, I look forward to your confirmation that my appeal has been accepted and you will not be seeking to recover this charge from me.
Yours
