We need a reply message to the Despatch Advice, in case a user want to revent a failure in the delivery e.g. because the delivery lokation is closed.

Currently the receipt advice is a reply on the receipt, not on despatch advice. Therefore, the proposal is 

a) Change the Receipt advice definition so it also can be used as a reply to the despatch advice

or

b) Make a new document type called Despatch Advice Reponse with a similar content than the receipt advice