It's unfortunate to say I never finished this story, like many of my other works in progress prior to this time. However, it is the furthest I got in 2015. Here is what happens next in the form of a summary.
The Chipmunks and Chipettes work for one more week. This week is more successful than the last week. Fortunately, this is their final week of working. It is noticed Dave's leg is healing from his injury.
.... and unfortunately, I do not remember much about the specifics. But the story is happy in the end and all conflict is resolved. One thing I do know about the specifics is how they all make a vow never to get a job at Walmart again.
I don't blame them. In some facilities, you can hear the refrigerators and freezers SCREAMING. Just joking though, they made the vow because they found it too difficult and overwhelming. Maybe they'll try a smaller clothing store when they're older and can legally work? lol.