CPP is part of ParkingEye. Have you complained to PALS? If not, why not?
Why did the driver not anticipate possible delays, knowing the state of the NHS at the moment?
Did the driver not attempt to pay the required tariff once they knew they had exceeded the 30 minutes free parking? The sign does not state whether the tariff is payable on entry or on exit. As they use ANPR, all they would need to see is evidence of the appropriate tariff having been paid.