As others have stated you need to record either through video or photo the abuse taking place, file a complaint to the police, animal control, and the humane society, and if necessary report it to the local media. While an animal is an animal, that still doesn't mean that two dirt bags should have the ability to abuse it. I hope you are able to find a peaceful solution to this issue, especially for that puppy.
"Surpress all compassion and you bear a weapon far greater than any held in the hand." - The Psychology of the Assassin