At last, you're back on the regulatory track.
Your account doesn't suggest that you have a defence against the contravention i.e. you were parked on 24/7 DYL without an exemption applying e.g. displaying a valid BB, loading/unloading/collecting/delivering goods which could not have been effected without parking where you did etc. IMO, collecting medicine/prescription from a pharmacy doesn't meet this test and there's no evidence in the photos of you returning with such a load.
In these cases IMO you have to look at procedural issues, in your case whether a PCN was being prepared when you drove off or whether all that the CEO had done was activities preparatory to creating a PCN.
You were there, we weren't, and your account is thin on this point.
