To answer your question, sometimes the LA miscite the full PCN charge before the discount is due to expire, the last day of discount is 20 June (if I am not mistaken), so screenshot PCN portal on that date. Other errors are if the PCN portal says it may increase to a charge certificate rate on a date they are not permitted to (won a dulwich bus gate appeal on that), or if they cite a different date to when you submitted a representation/PCN challenge, however their portal seems different in recent times and these errors may not occur, so you should consider other appeal points. The most effective way to win the PCN is on administrative technicalities or if the LA mess up the enforcement process or make a procedural impropriety. However, it would be useful to know when you approached via college road, what did you make of the advance warning sign before the roundabout? Whilst merging off the roundabout what was your thought process? Were you unfamiliar with the area?
