Were the eggs shipped? Sometimes the rough shipping can cause malpositions. At any rate, I would prop them up so the pips are higher than the rest of the egg so they will not drown. When they hatch from the wrong end they do not have the luxury of an air cell to pip into, which leaves them vulnerable to drowning in the remaining fluid inside the egg.
Have you read through Sally Sunshine's guide to assisted hatching? It is very helpful with these situations and tells you exactly what to do for malpositions and when/if you need to help: http://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching
I had one pip the wrong end, but then she got stuck and could not turn in there to finish hatching. Sometimes they can still make it out on their own, just have to be patient and look closely for the signs they are ready to hatch (you can read more in the above link). But basically, once all the blood has drained from the vessels in the inner membrane of the egg, they are ready to hatch. Before that they are still absorbing the yolk and you would risk causing a bleed from broken blood vessels as well. My girl made it out after a very long, slow assisted hatch from me (which is how it should go, no need to rush as rushing things is never good in these situations). She is a year-and-a-half old now and my favorite duck ever.
I don't have any experience with Call Ducks specifically, but they do sometimes require assistance due to their short bills. So yours probably will since they are also malpositioned. Just take things easy and slow.