Free Traffic Legal Advice

I drove to Luton airport to drop off some family members who were going to fly overseas. Instead of using the regular drop off service , I wanted to drop them off in the free area (15 minutes free). I had no idea that this does not exist anymore and that it's only longer parking. After I turned into this area I saw the signs and realised I must get out of there. I reversed my car a bit, my passengers hopped out, and I received a PCN for "Dropping off or picking up outside of designated areas." Is there a way to get out of this? It was truly a mistake of mine to turn into that street.