I work at a t-mobile store. I had enough customers come in with issues concerning that movie file that I ended up making a copy of it to provide an easy remedy. Some people don't realize that the movie is on the SD to begin with and they toss it in exchange for a larger one. I figure that its simpler to just copy the movie to the new card instead of hassling with exchanging phones/sd cards out.
Anyway, I would just go in to your local store and see if anyone working that day has a vibrant with them (if not see if they have one that was returned). If they're nice/competent, perhaps you can just have them make a copy for you.
As for your BAN, it is normally printed on the receipt (listed as account number or similar iirc). If not, you can get it through the online account management or by calling 611.