Ok, assuming that you didn't get a windscreen PCN - APCOA have failed to issue the PCN within the required 14 days to transfer liability from the driver to the keeper. In general APCOA don't litigate, but you could try a complaint, which they should treat as an appeal. Make sure you write only as the keeper, any reference the the driver being in the 3rd person. Something along the lines of
"I am writing in reference to your PCN xxx re Vehicle YYY. I am the registered keeper and have recently returned after an extended overseas trip to your PCN and subsequent 'debt collection' letters. I am under no obligation to name the driver, and will not be doing so. Your PCN was issued too late to transfer liability to the keeper under the POFA, and I am therefore unable to help you further in this matter. I look forward to your notification that this PCN has been cancelled.'
They will probably just waffle on that it is too late as it is now in the hands of the debt collectors, but it puts them on notice you are not a push over.
