That's terrible. My dog is a roamer. No matter the love attention,food we give her, she plays at other people's homes.
I'm ok if she doesn't return.
Take one problem at a time.
A plumber once sold me some good stuff. I think it's called RID. It's a powder you put down the drain.
Bake or buy a treat for neighbors. Cookies or wine. For their former care of cats. ( not current rudeness.