I recently found a lost, healthy, boxer/mastiff mi...

I recently found a lost, healthy, boxer/mastiff mix with no collar. She is very playful outside but wont come inside where it's warm. Right now, she is in my backyard. I called the Richmond Animal Control so that she'll at least be out of the cold while the owner is being located. They told me someone would be coming by today. That was at 10:00am. It is now 6:45pm and no one has come. I called back an hour ago and was assured that an officer was on the way today.
I understand a business being busy. What I do not understand is a business making false promises when the potential life of a lost animal is on the line. It will be below freezing tonight and I have no way of helping this dog stay warm.