Back of PCN, please, as they sometimes make fatal errors in the "small print", plus post a GSV link to the exact location where parked.
Your reps need to be based on your narrative here. You are claiming the loading exemption to yellow lines, double or single. Make sure you tell them you spoke to the CEO who said he would make a note about the matter. You will need also to describe the goods being unloaded, (weight and/or bulk); a photo could be useful.