DPD Pickup Parcelshop

In just a few weeks, on two occasions DPD service didn't deliver my family's packages.Two weeks ago I ordered a Xmas present for my family member via Amazon, and it was to be delivered by DPD. On the day of expected delivery, although all 4 members of the family were at home, no one heard the doorbell or a knock on the door or the noise of the mail slot being opened, but in the evening a piece of paper was found lying by the doormat saying that the delivery was missed (the courier didn't even bother putting the paper in the mail slot, he just threw it on the ground) and hence I now needed to pick the parcel up from a DPD pickup point. Yet in my Amazon account DPD updated the status as Delivered". I contacted the seller of the product (Singer Ltd) explaining the situation and asking them to contact DPD regarding this. Their customer service emailed me back saying that DPD will give me an update regarding the new expected delivery date and in case I'm not happy with it