I park services ltd It says its a parking charge notice. Its £160

They keep sending me letters

I parked in a carpark that i have parked in before only to find they had changed companies and the parking meters. The meters were not able to take cash and i didnt have my bank card (as i had been at work) and it said pay through the website. I left the carpark but then ended up with a fine as they had me on camera. This was in November. I have filled out several appeal forms on their website and wrote letter, but they are still saying i owe the fine and ignoring my explanations of what happened. They have now added chargers aswell. What do i do next.