So because they are just asking me to pay them it's neither a fine nor a penalty? And I don't have to pay? Surely not as simple as that!?

Hi, I parked at the PPS car park opposite didcot station and forgot to pay. I realise that it is my fault for not paying but I park there via the ringo app every day. I appealed the fine as its £60 and thats 10 days parking!!! Surely they can't charge this as thats a penalty? I did offer to pay for both my car and also another £6 for any car that would've taken my place. They have since rejected my appeal and sent me this: "Thank you for your appeal which we will respond to below. Firstly, however, you should be aware that as you have not given us a full serviceable address for the driver of the vehicle we will be making a request to the DVLA for details of the vehicle keeper so that we can establish the identity of the driver according to Schedule 4 of the Protection of Freedoms Act. Further to your email of appeal received on 23/12/2014 regarding the above parking charge, I have now had the opportunity to review this case and my findings are below. Whilst we appreciate and sympathise with your situation, we are unable to take mitigating circumstances into account. Parking at this site is only for vehicles that are parked in accordance with the site instructions, as detailed on signage on site. This signage is clear, in excess of industry standards and clearly details any charges that may be imposed should these restrictions be contravened. The amount sought as the parking charge notice is a term of the contract. Vehicles must be parked only in designated areas with a valid pay and display ticket clearly on display on the dashboard of the vehicle at all times or have an active RingGo session in place. There was neither a ticket displayed in this vehicle or an active RingGo session and I therefore uphold our operative’s decision to issue this parking charge notice. It is your responsibility to make sure you have either a valid pay and display ticket on clear display or an active RingGo session in place for your vehicle at all times. If there is neither a valid pay and display ticket displayed in your vehicle or a valid RingGo parking session then your vehicle is not authorised to be parked at this site. There is no active RingGo session at the time the charge ws issued to the vehicle and therefore the charge was issued correctly. We are therefore unable to cancel the Parking Charge Notice as it was issued correctly. Please forward a payment of £60 to reach us by 20/01/2015 or £100 to reach us by 03/02/2015 in order to avoid Debt Recovery proceedings; incurring additional costs. Please be aware that when appealing any further the charge will not be placed on hold. Payments can be made by cheque or postal order - payable to PPS Ltd, or on our website - If your appeal is unsuccessful, you have the opportunity to go to an Independent Appeals Service known as POPLA (Parking on Private Land Appeals)." Is there anything I can do? Am I likely to get out of it? Cheers!