Cellphone ****** outside event

I was at the John Legend concert. And after the concert when just leaving the venue, there where groups of guys just waiting at the exits. My wife and I tried to walk past them to get to the car and they just accosted us, there was nothing we could do. It seems like ticketpro dome only cares about security in the event , when you are getting to your vehicle , you are on your own as they allow anyone into the parking area. I will definitely not be using their services again.