Allsorts, not sure who you have been trying to use for these deliveries. You must complain about the one that was thrown over your gate, or just inform the company that IT NEVER ARRIVED.
I have to admit that I do use on-line for many purchases, and rarely have any real problems with them.
Do find the tracking systems only really work when the item is about ten or twelve deliveries away from me. Very useful then, as I can then actually watch to see when I am the next (or next but one), delivery. Then I am often actually sitting by the Main entrance to our flats, waiting for them.
Deliveries do have to take a photo of any delivery that is NOT actually into your hands, these people are often working under dreadful time restraints, so if you do not answer the front door bell pretty quickly, they do just leave it.