UPDATE: (to the update)
I just got a call from the LV store and they informed me that they were unable to fix the zipper to a satisfactory level, so I can come in and get store credit and get something else. I'm actually really surprised that this was the result. Happy, but surprised. At this point, I think I might give up on this bag for a while and pick something else out. One thing, I didn't ask, is how long can I keep the store credit for, since nothing is really on my list right now.
When I got store credit earlier this year for something they ended not being able to repair, I don’t believe there was an used by date. I did spend mine within a few months though.. basically got a replacement of the same wallet.