I need help on deciding what to do with my rude thoughtless neighbors?

Before I went on vacation I asked my neighbors if they could watch my two cats, I have had the cats for eight years, I told them I would pay them a good amount of money and provide all the food, while I was on vacation they had called and told me that the apartment manager had called animal control and they were in the pound I was so upset I called animal control to asked what had happend, well it turned out they had called animal control because they did not want to deal with the animals, also animal control put one of my cats asleep, I am so so upset, one of my cats is dead and the other is in a foster home, I can't find her anywere, my neighbors did not even say they were sorry, they basically said "oh well", what should I do, is there anything legally I can do, please help..