Help... I got a BIG problem!!?

HI, I have a big problem that I really need help with so any imput would be really helpful!! I have a neighboro that has horses just like my family. Well her husband is a pastor and they moved away a few months ago because he got moved to antoher church but, they left there horses. A few weeks after they moved a family they had rented the house moved in. We assomed they were taking care of the horses but, our other neighboros living on the other side of the horses said that the lady came down to feed them but, they havent seen her in a week and the family said that they never touched the horses. My family has done everything for the owners. 2 of the 3 horses have gotton out twice and my grandpa and I have put them in our pasture with our horses and feed them with our own money. My dad has fixed their fence both times. We can't keep doing this. We have called multipul times and have facebooked them but no answer. We don't want to have to contact the police but what choice do we have?