UPDATE
First of all Thanks for all your comments again. When I wrote this post, I was extremly angry and sad because how they treated their customers. I wrote a letter to headquarter boss and yesterday I got the calls from her and BalLv manager. Also they sent me a shoulder strap.
They said sorry and the manager did not get the any messege from SA.
For the security cam result is, the manager told me that she checked the cam but she could not find it out because she could see only bag in the dust bag (??) Which I do not believe it. If the SA checked it before the bag shipping out, there were something on the cam. or She did not check the bag.
I got the shoulder strap earily in the morning but I still do not sure to keep it or return it.
Because they have only store credit available, not refund.
I am going to business trip to NYC so I called BalNY and BalLV to exchange the item at the BalNY store but they said to me,If I wanna bag from NY, NY store going to shipping to LV store and LV store will shipping it to me. ???????Weird.
So I need time to think which is the best way to get a bag or keep.