Thanks for the quick response. Your advice is clear. However, what should I do if they do indeed start court action?

The car park for the Maternity Section at the Southern General Hospital in Glasgow was full on the 20th April this year when my daughter went to give birth. Part of the car park was closed for maintenance work and the workmen pointed us to an area where other cars were parked on a side road within the hospital. When we returned there was a notice on my windscreen from CPPlus notifying me of a £40 Unauthorized Parking Notice reduced to £20 for immediate payment stating I was not parked in a designated parking space. All the cars parked in this area also had similar notices. Another driver who was there advised me not to pay and to ignore any follow up. I then received a letter dated 4th June 2015 from PCS Parking Collection Services advising that they had obtained my details as the registered keeper/owner of the vehicle and stating that full payment must be made within 28 days to avoid further action. As originally advised on the 20th April in the car park I continued to ignore this letter. I have now however received a follow up letter dated 3rd July 2015 from DRP Debt Recovery Plus Ltd demanding payment for the unpaid parking charge of £40 for their client otherwise they will recommend their client that court action should be taken. I'd appreciate any advice on what action I should now take. Thanks