My first experience was when they delivered a £2000 PC to the correct numbered house but in the wrong street! Then had the audacity to send me a photo of the number which apparently proved they had delivered it. Luckily I took the time to wander the streets in my general area and found the 96 that they had delivered it to, and the person accepted that I was the recipient.
More recently I paid £8 delivery and they gave me a delivery slot and then after I waited in for them the time slips by over 30 minutes so I called them and the woman I spoke with said it was back at the depot with no reason!!! No card, no explanation. After that call I got an update email stating it will be delivered too late for my purposes on Monday, utterly useless company. I intend to check every time I want to buy with a company if they use DHL and if they do I wont do business with them unless they use a different company.