Yeah no, I tried again, I was able to *get* a contract this time after Day 2, but there is still no way to *complete* contracts.
You complete contracts by choosing one and making scenes to progress it, you can set the auto sell button on ON to automatically sell your scene when all the images are made or by clicking on the sell button under the scene that you make (you can check the number of images already made by hovering the scene in the menu, the number is in yellow).