Hi Sweetliberty,
Great help weren't the neighbors. It would have been nice if they said they were too busy or something. Instead, they let it all go. Not nice. Not great to come home to at all. I would be infuriated also!
The cat is a bummer. I send my best wishes getting rid of the cat. I had a similar problem a while back. It nearly drove me insane. :) Most cats come and go but I had one who was a major problem. The people who owned the poor cat nextdoor never let the cat in day or night. The cat turned feral. You are right, trapping the cat is probably the only way. Then we can hope, maybe it can get picked up by someone who will find it at the shelter.
I hope, regardless of this situation, you got to enjoy your trip away. :)