Pls see attached. How do I apply the loading exception it was heavy 10kg and what do you mean by only in exceptional cases should the PCN be posted to me?
The PCN has been served by post because, according to the CEO notes about your vehicle, you drove off before the PCN could be served to the vehicle or driver. Yet you say you saw no CEO at any time, or any PCN, so drove off after making your delivery.
I have to say that carrying a 10kg parcel any distance to a post office would be a struggle even for somebody in good health, so I think you have a good case, but you need to prove that you made this delivery. You should have some sort of receipt, and maybe a work instruction, so include copies of these with your representations. If you have a document with the parcel weight also include a copy of this, and any more details you can obtain.
So why not write out a draft of what you propose to send and post it up here for a review.