If they were really serious about their mission and the dog's health and wellbeing came first, they would have, at the very lease, allowed you the courtesy of another pick from the facility. Unfortunately, they probably adopted some rules that have now become dogma.
On the brightest side you can make of this, at least the little tyker was able to spend some time with a family that truly was glad to have him. After all, that was probably his greatest wish. You made it come true.