DHL — dhl clearance delay

The dhl clearance team is delaying the delivery of the shipment for more than a week now, saying that they dont have the invoice if the shipment and asking the end customer to provide it. Hope the company understands that the invoice is handled and recieved when they recieve the respective shipment, if you have missed it or misplaced it, why is that the end cusomer has to suffer for the shipment delay?
Taking this ahead, we are oroceeding to file for compensation for not getting the required documents / processes done on time. After a long delay from dhl kyc team now its their clearance team thats delaying it saying they dont have the invoice with them.

The parcel was expeced to be delivered on dec 17th and still nothing has happened.