So your bus was on the 23d, and your saver day passes are for the 24th and the 25th? And you would like to move one pass to the 23rd so you can use it for your trip to Luzern, is that what you want?
Busses are not a reliable way to travel long distance in this part of Europe, as you have found out.
You cannot move your saver day pass, nor can you have it refunded. But you can travel by train from Milano to Luzern. EC 178 leaves Milano centrale at 10:10, and you can currently book it for 34,50 on Trenitalia.
