Walmart Rage

I try to avoid going out at night by myself or kids, but last night I took that drive to Walmart. Little did I know I would soon be reminded why its not safe to be out with so many nuts walking, driving around.
My 16 year old and I went to get a few supplies I needed for shipping. The Walmart was packed, lines were long, toddlers screaming, and a full line of customers trying to return items. I quickly got what I needed and got out. That's when it happened. I'm backing out of my parking space, I didn't see another SUV doing the same, she honked. I stopped, honk and see the space in front of me is empty, I drive through it. As I'm driving the woman is screaming at me and I roll down my window and wave her away. No I did not flip her off as much as I wanted to or scream back.
"Geez, lady what's wrong with you?"
It doesn't end there.. She cuts through the lot and almost hits me forcing me to suddenly stop, my son is getting angry. I don't say a word and turn my car to leave the other exit. She follows and blocks me again, still screaming who knows what and flipping me off. She has a 8 or 9 year old doing the same. I see the security guard surely he's seen this confrontation and will help me. NOT
I park next to him, while the lady is still yelling and circling around my car. He finally rolls down his window and when I roll down mine she comes running to it and starts yelling. Challenging me to get out, how dare I honk back at her!! Really lady!! Get out and fight over a honk?? She's telling me obscenities and my son had enough. He starts yelling at her and I quickly tell him to stop. Why you ask? Because unlike her I'm teaching my son that some things or people are not worth it. The security guard never gets out of his car. She finally stops screaming, get in her car and slowly drives off, waiting for me to leave. I ask the security guard "Hello, where were you?? You were supposed to help me!" All I get was, "was she yelling at you??" I'm angry, I call and report her plates, description to police. Of course they do nothing but take a report. 
Last time I ever shop at the Walmart and I will think twice when asking a security guard to help me to my car!! Crazy world we live in, where I can't sleep worried someone will come through our window and snatch my kids or a ticked off, road rage Walmart nut will drive me off the road!!
What would you do in this situation??