Just a thought... Could it be these employees didn't call the police only because they've been told not to by their management? due to "policy"? They might be grateful for customers who are proactive as they feel they can't be. Most shoe stores where I live have young, starter-job employees who just have to follow the rules set up by others. Might be the reason for the disappearing salesmen and the "just pretend he's not there" attitude of the sales-girl.
oh, and hope you have your cell phone on you all the time now. Not being able to call for help yourself definately made a bad situation worse. Personally, I have a handbag with little pockets where my cell phone and my taser (shhh, don't tell!) are easily accessible to me.
Your kids will learn a lot from how you handle this situation. More than you could ever teach them. You never know, this could prepare them to deal with a bigger issue in the future. Hope it's a one time thing, but you can use it as a teaching tool.