Last week I left my car parked up on the pavement front and rear wheels parked up nearside.Four metres in front of me there is a sign on a post showing parking on pavement allowed viewed from my windscreen and just beyond that many cars parked up on the pavement.I have now received two penalty notices(Ileft the car there for several days).I've gone back to the "scene of the crime" and noticed that on the reverse of the parking allowed sign it shows a parking dissallowed sign which could only be read if you obviously had gone beyond sign and come back on yourself!Do you think I have a good reason to challenge?..Also has a second "offence" been committed,as I've only parked there the once but they've charged me over two consecutive days. I'd appreciate any help thanks.