Clearly the basis of any reps you submit must be the loading exemption. You need to fill out on the weight and bulk of the goods, and why it was necessary to park on DYLs to do the unloading. However, as you will find out, the usual response to a submission of a challenge, is for the council to send out a Fob-Off letter refusing it.They do this because they know from experience that most people, (>95%), then cough-up to get the discount, not knowing much qbout parking law. Is this you ?