This seems quite simple; the idiot CEO has served a PCN with the wrong contravention on it, because there is no requirement for people parking to pay and display.
So submit representations saying that the contravention did not occur because there is no requirement to pay for parking at this location. You could also request that the council provide evidence of signs stating that payment must be made to park. If they show the signs you have shown us, then they shoot themselves in the foot.