Just taken a Christmas delivery and DP reminded me about something that happened a while ago. Feeling a bit mortified on reflection! 
I ordered some shoes in-store at Kurt Geiger, got home from work to see DPD had tried to deliver and the card said to go online to book a new slot. The next morning I went online to rebook and see the next slot was the next day, at lunchtime so I could be home from work to accept the delivery.
Then later that day, I was home from work, saw the DPD van pull up and notice it's the exact time I had rebooked for, but it was obviously the day before.
Thinking I'd made a mistake, I went out to the driver as he delivered at the house opposite and was looking like he was about to drive away, I showed him my card and asked if he has my parcel, he checked the back of the van and he did. So be scanned it and said that he couldn't give it to me as the delivery was cancelled that morning (at the time I'd gone online to book a slot) and it seems that DPD had put the parcel back in the van to reattempt delivery that day, despite the fact that I hadn't booked a slot myself at that point.
So when I'd gone online, I effectively "cancelled" it from his deliveries that day, in favour for delivery the day after. Odd system.
Anyway, I said to him, well look you're here now, as am I. I really want that parcel, so please can I have it. He refused. Said he can't. So I asked him to call someone senior to ask if they can authorise it, he started to get rude and said no. I understand they are under pressure for deliveries, but I was frustrated by his rudeness and just being a bloody-minded jobsworth. I'd been extremely polite to him.
I pleaded with him, to please call a supervisor, he's stood there with my parcel and I can't have it.
Again he refused and lobbed my parcel into the back of his van and started to close a door.
I saw red at this point, the way he threw the parcel and his manner tipped me over the edge.
So before he could close his second door, I flung myself into the van like a mad woman and sat in it, with my legs dangling out of it and said I wasn't moving until I got my parcel. He was speechless and said I need to move. I again asked politely and asked him to call someone to get authorisation to give me my parcel.
Seeing I wasn't budging, he complied and rang someone. I heard them say to him, "Of course she can have the parcel, don't be so silly!", so sheepishly he gave me the parcel.
I thanked him, apologised for my drastic action and went back inside.
My shoes are lovely by the way. (See pic).