Cel Parking County Court Desperate for advice

[TraceyH29]

6f4c882c-7edd-4b8b-9c7e-d9b492e0c89a.JPG I wonder if any one can help me, we run a drainage company and had a job at a property we were unaware at the time that this was private land and to be honest due to the fact we were completeing work we thought that it would be ok, we drove onto the land and when we arrived we were told that we needed to go to the front of the property so drove straight off, a month later we recieved a a pcn through the post and then later a letter from zzzp. We stupidly ignored it because there were no pictures of our vehicle and we was there a total of 12 minutes literally enough time to drive round look and then be told to go to the front. We have just received a claim form from County court business centre. signed by Civil Enforcemnt Limited. I have read a million forums and fill completelty overwhemled by the information. If the area had a ticket machine or it was evident that I would recieve a fine from just driving round and coming out then We would of known what to do. But there was nothing. The fine we have now recieved is £322.59 we've never had a parking fine and Im really out of my depth with the information, do I just defend it by letting the court know the facts, i.e we was working, there were no evident signs, no car parking payment facilities. or do we pay it.
The area that we went along is also known as a service lane, which as we were providing a service it would make sense to be there.
Ive attatched a photo which is as you go into the area. as you can see the parking signs are on the wall not visable until you have entered the area.
Also should we post the defence or send online.
Thank you any help would be really appreciated

[jaguarsuk]

ostell is the guru of all things parking, so will be along with advice soon.