Two sides to this - yes its a busy time of year for all couriers and logistics firms as many retailers and industries are bulking up on orders or processing more items but at the same time those same logistics firms should realise this and put on more staff to cope with the increased demand.
Better than HDN! Got a card through the post box, thought it had been left with a neighbour, oh no, they had left it up the side passage. How on earth did they get up there I thought... well they didnt, it was thrown, and left in the pouring rain! Muppets the lot of them!
Actually talking of DHL I rang to have a parcel re-delivered to work. They wouldnt do it as the work address was not the drivers area! Why advertise a service if they wont do it! It was only 2 miles away as well! They also left my Canon 20D at the airport once when I had shipped in many years ago, arrived at my address 2 days late! I avoid DHL where possible and any business that uses HDN.
DHL outsource many of their deliveries to independent couriers - the reason I was given a while back for my delivery arriving three days late was that they'd given it to the wrong Courier- I think they have a book of excuses and pick one at random when someone complains.