[mothered]

DPD never provide a photo of the person receiving the order, they only need to provide proof of delivery to the door

Total BS.

They've stated this In their very own reply:

photo evidence as you can see is of a person with the door open accepting the goods.

It reads "photo evidence as you can see Is of a person with the door open accepting the goods", so evidently they do provide a photo of the person receiving the order. Tell them exactly that, and to forward the actual evidence clearly demonstrating a person with the door open accepting the goods.