the relevant paperwork was not sent to any wrong address, you simply didn't see it as were not resident due to caring for you sick mother during Covid-19 Lockdown
even if OBS did, they have zero legal powers, their only option is to return to court and ask the court to assign court bailiffs to enforce the debt, of that you would get notification from the court first. As for DCBL, they can't involve their HCEO wing as the judgement is less than the high court £600 limit.
that is your only set aside reason I can see, but you also need a basic defence against the claim itself, to date I see no credible reason other than the claimant has failed to actually quoted what T&C you broke in their POC? overstay, didn't buy a ticket, outside lines etc etc.
you indicate earlier this might have been double dipping (2 visits) so an sar to OBS might help once you have the PCN and or the Notice to Keeper/driver.
can't see any harm in trying for a consent order to DCBL FOC to you on the basis their POC fails to state what you did wrong. they might agree.
if not it's gonna cost you £255 for the N244 set aside, but i'd get this in Monday.
reason for set aside - could not return home due to caring for your sick mother during Covid-19 Lockdown.
defence - the claimant has failed to adequately particularise their claim by not stating what part of their parking contract T&C's I have allegedly broken.
eitherway, by contacting DCBL with the above (free option - worth a try)
or Sending the court an N244 to northants bulk (£255)
for either you do not need to wait.
If you have a read through some other VCS or Excel (both companies are run by the same shyster) airport threads you'll soon get the idea.
Airports have their own bye-laws which a private company can't override so you don't owe them a bean.
You do need to reply with a snotty letter though to show Simple Simon that you know the law and he'd have a fight on his hands if he took you to court. There is an excellent example in Northmonk's thread (post 50) which is currently four places below your thread.