First question that comes to mind is, was the suspension sign put up on the sign you observe on a daily basis ?
Second question is, on the day you saw the PCN on you car, when was the last time you had looked at the sign ?
Suspension was for Wednesday 23rd July, for a house removal, so one would expect the sign to be put up on the Friday of the previous week, as it is not an emergency suspension. Putting it up on a Monday is a bit too late, IMHO. as that gives only 2 days notice.