"Good hospital, poor parking"

I've had reason to visit Sammy Johnson a number of times and have always been served well. However on my last visit I couldn't pay for the parking as there was a chap servicing the machine. I tried calling the automated service to pay by card but it wouldn't allow me to. I was in a different car to the one registered on there system and to change the car i needed to input the last 4 digits of my card, trouble is I changed banks a while ago so no longer have the same card. As I couldn't input the correct digits the automated service hung up on me, I tried 3 times to no avail. I explained this to a lady from the hospital who was with the chap servicing the machine. She told me to give my registration to the lady on reception, and when she had finished outside she would collect the registration and put me on 'the exception list.' I presume she forgot to do this as I have received a parking charge. I have lodged an appeal with Parkingeye explaining the above but they sent a letter basically saying I didn't buy a ticket so I will be charged. I've now lodged an appeal with POPLA.