Okay, I sympathize on the fact that your horse got a screw in his hoof, that really is unfortunate. However, keep in mind that you were the one who decided to place your horse in someone else's care. I know that not everyone is able to keep their horses on their own property, which is where boarding becomes very handy. When you do board a horse it is your responsibility to tour the facility, get to know the owners/managers and make sure that you feel comfortable keeping your horse with them. If this place is really that unfit for horses, and the management really is that bad, wouldn't you have picked up on that in the beginning after meeting the management and touring the facility?
But on a positive note, set up our new stalls at the new stable today :) We are trying out rice hull bedding. It is totally self care at the new place, but it is basically in my back yard (1 miles away) so I think it will be great.