I ordered something from Thinkgeek once. It got from New Jersey to Montreal in two days, and it took them a week to actually get it to me. They'd no-show on days customer service told me they'd deliver, then they'd deliver on days customer service told me they wouldn't be showing up. That was the day I learned the value of shipping things to work.

I had a replacement MacBook power adapter shipped out. They left a notice once, and then customer service told me that there'd been three failed attempts and no further attempt would be made. When I asked where the package was, the agent didn't seem to know, but guessed that it was at the depot. When I got to the depot I gave my delivery slip to the guy behind the counter, who came back and said he couldn't find the package. I told him to go look again and this time he actually found it.

I ordered a kit from 23andMe. DHL tried to deliver it once and then returned it to sender. I got them to send me another one (at a $25 fee), which DHL never delivered. I tried a third one, and this one was "at the depot". I went there and waited an hour in a small cement room with nothing but a chair in it while they looked. Eventually they came back and said they'd given up.

Every single encounter I've had with DHL has shown they're completely incapable of performing the core aspect of their business: getting a thing from one person to another. Worse still, they don't really seem to care or even understand that a screw-up is happening.