Should I go with a very simple informal representation then, as follows?
'The height of the signs that I passed marking the start of the pedestrian zone are excessively high and the positioning irregular. It is highly unlikely that a motorist turning off the high road onto this street would be able to read them. This was the case for myself when I turned into the side street - I did not even notice the signs due to their excessive height. Thus, I would ask that you cancel this PCN and also conduct a full review into the height and positioning of these signs.'