Euro car parks fine -meters broke

Hi everyone. I need some advice.

We received a PCN from euro car parks demanding £60 for parking without a ticket. The 2 ticket machines next to each other was faulty and so the driver left a note in the windscreen to say that both ticket machines is faulty hence no ticket, thinking that if the car park is patrolled then with the note it wouldnt be a problem.
The driver looked at other cars parked and none had a pay and display ticket.

Approximately a week after, the driver received a PCN and appealed it and the appeal was rejected and now got a POPLA code.

At the time, stupidly the driver didnt think to pay by phone as he didnt see the instructions to pay by phone as the sign to pay by phone with the location number etc isn't next to the sign stating the hourly rates and the driver completely missed that.

The driver didnt think to take photos either. Going past the car park later in the evening (we left in the afternoon) , we saw that some cars had a penalty ticket on their windscreen.

I have read through the forums and i found a very similar one -february 2017 mr Benn.

(as a newbie i cant post links)

Are we alright to use the appeal letter to POPLA from 2017 mr Benn (altered to our situation)?

Thanks in advance.