Ive never been so angry! sorry long

This past summer we got a phone call that a senior Rottie had been abandoned in a garage.We took her in and she was placed up for adopting after a few weeks.A  couple of days later i got a call from her owner.She said the dog had not been abandonded but the person who contacted us was her dog sitter.They seemed very happy to get her back and i was glad they had been reunited.About 3 weeks later she called and said she had to leave town on a family emergency and asked if i would watch her.I agreed and kept her for 6 weeks.She was healthy except for some hip problems and arthritis but was still a happy girl. A couple of weeks later i got another call.She claimed that she could no longer walk and had lost control of her bowels.She said she didn't like the kids climbing on her and didn't like the new JRT puppy they just got.She claimed to have taken her to vet.The same one i go to.She claimed that the vet told her she needed to get rid of the dog for her childrens health.Even though he wasn't supposed to, the vet told me that she had never been there.I told her i couldn't take her in right now,we didn't have room.I also didn't want to make it so easy for her to dump her sick old dog.She started running ads looking for a home for the dog,she repeated them every week.No mention of the health issues except HD.[linkhttp://www.s135407385.onlinehome.us/applications/ClassifiedListingsManager/inc_classifiedlistingsmanager.asp?ItemID=18204&CategoryID=177]http://www.s135407385.onlinehome.us/applications/ClassifiedListingsManager/inc_classifiedlistingsmanager.asp?ItemID=18204&CategoryID=177[/link]Fast forward to this weekend.Browsing petfinder i came across this[linkhttp://search.petfinder.com/petnote/displaypet.cgi?petid=7642996]http://search.petfinder.com/petnote/displaypet.cgi?petid=7642996[/link]It looked enough like her i had to go look.She looked so bad i wasn't sure at first so i had them bring her to the viewing room.She came right to me and huddled between my legs shivering.I pet her and her hair was falling out in large bunches.After a few minutes my hands were grey and slimy.She has chewed deep holes in the front of her legs and her nails are cracked and broken.She had a very hard time walking to the room.My heart just broke.She had been found abandonded tied to a tree in the housing area they live in.I told the AC officer what i knew and even directed them to her ads.They said there is little they can probably do! She said if they were to do anything it should have been done when she was picked up.Why cant they do anything? Her own ad is proof that this is her dog.It was picked up by police right by their apartment!Why cant anyone do something about this.If people arent held accountable the problem wont get better. I am just so disgusted right now.I couldn't even take her home today.My MIL gave me a ride there in her new car so i couldn't ask her to put this big dirty dog in there.I really feel like a heel making her stay there another night.She is so scared and confused.Dont worry folks im springing her tomorrow morning.