There were no documented accounts of anyone facing punishment for refusing to kill. They were just assigned to a different unit. Unfortunately there were enough willing participants that would fill in. Read “The good old days”.
No, they were sent to “punishment units” on the Russian front lines(which the regular units detested as it was seen as a dishonor to the heroism of the front line soldiers.
And if they were already on the front lines, they were simply shot, according to the discretion of the officer.
And given the hectic state of the retreating Wehrmacht, paperwork probably wasn’t a priority.