The delivery is not Dells' fault, it is up to the delivery company. Delivery between 0800 and 1800 is very common now and should come as no suprise as it is quite clear on their website. You can always arrange to pick it up from the depot as I have done with many Dells.
If they delivered to a neighbour and it wennt missing or was faulty you would be the first to complain. They will also deliver to your work address if you arrange it with them.