I’m sure my current experience isn’t unique - typical frustrations of a delivery company.
Why do they - or at least some of their operatives - lie openly?
Why do they have doom-loop communication channels which preclude any resolution of issues?
Why are their Customer Service Teams fully automated?
Do their phone queues actually have anyone answering calls or do you just sit there until you die?
Try Evri , they are awful as well
I am not alone 
God I do n’t like them…
Our experience has been that Evri are much better than they used to be.
The Wine Society use DHL - I now don’t buy wine from them as lost and broken deliveries became the rule and not the exception. Tredz also use DHL. I ought to select my online traders by checking whether they use DHL - and boycotting them (with explanatory email) if they do…
DHL are a disgrace, followed by Fedex. Evri depends on who your local delivery person is.
Yes Royal Mail - having some work done to the front of my house and Royal Mail postman won’t enter the premises you would think I’m decommissioning a nuclear reactor but funny the Amazon guy never fails to deliver in one case ten minutes after the Royal Mail postman said there was no access.
No delivery company wants to use our doorbell, a quick knock and dump on doorstep.
They take a dump on your doorstep? Surely that’s taking things too far 
The local fox does that
At least they’d be delivering something there!
It may be some statistical outliers? I would give DHL 5 star plus if I can, never have had any issues with them for shipping items from the US to UK and vice versa. They are extremely fast and reliable.
This does seem to vary considerably from one locality to another…
For example, I have found that the most dependable, by far, is DPD - to the point that on the odd occasion I have selected one supplier over another based on them using DPD.
However, I’ve seen others claim they had terrible service from them.
This, I have concluded that personal, or local, experience is the only reliable measure!
Overall DPD for us, the local guy who delivers has a smile that lights up our day. We did have problems with a wine cooler, twice, broken before they left their depot…..poor packaging in our opinion,
I was more concerned about who was getting a quick knock!
I get that the final courier is often the variable that determines the end-user experience, but the built-in inaccessibility, doom-loop IT set-up, complete disconnect between spiel (‘polite, helpful & professional’) and reality (you can’t speak to anyone) etc just portrays the whole organisation as being contemptuous of the user. I’m reminded of Trump….
I know some are not fans of Amazon……..but any problems by them delivering or a 3 rd party have been settled in my favour, very quickly. They used to be cheaper, now i often pay a little more with Amazon over how they handle disputes.
The royal mail sent my Amazon order to a different address, said it was delivered. I contested, royal mail gave the exact gps coordinate and pictures……of a different property. The seller would not budge, Amazon gave my money back…..choices i guess.
Agree, much as I’m uncomfortable with the concept of Amazon, their service and delivery are actually 2nd to none…..
Mrs AC had an unexpected delivery earlier in the week left against the front door. The card in the letterbox said the parcel had been delivered to a neighbour. I suspect it hadn’t and was just left outside and the driver couldn’t be bothered to try a neighbour.
In fairness to all the delivery people I think the vast majority of things are done well, but I tend to go for Amazon where possible due to their excellent customer support and am very aware these days to use a credit card rather than a debit card due to additional protections.
Admittedly I often order things to be delivered when I know I’m at home but it can waste hours checking the apps for current/revised delivery times.
Special place in my heart for the DPD van driver who managed to rupture his fuel line mounting a large kerbstone and then leaked diesel over my driveway, my neighbour’s driveway and all the way down the road until he ran out of fuel about mile and a half away.