Quite right, Parking Contravention Charge it is on the plastic sticker too, now that I've checked

Issued by NCP - (not NPC) and says penalty charge at top.

I parked at an NPC station car-park, but the machine was out of action. My coins wouldn't insert, and there was a flashing message on the machine's screen saying "Out of action". I didn't have my mobile with me, or any plastic so I couldn't pay over the phone, and there was no other machine in the car-park. I got a penalty on the car when I got back, and I wrote to NPC stating the circumstances and saying that I have no intention of paying their excess charge. NPC have "rejected" my letter, saying the parking attendant would have checked the meter was working before issuing the notice, and there was no fault reported on the machine. It seems that either NPC are just sending a pro-forma response and haven't really run any checks, or they have made an error, or the machine had an intermittent fault that corrected itself. Knowing nothing about the technology don't know whether this is possible. Anyone with similar experiences, or a possible solution?