Maybe you should tell them they will be billed for all the food, vet bills and up-keep of the cat AFTER they prove that it is theirs. That should stop it.

It worked for me with Luke anyway. I had a neighbor kid saying he was his cat. I told him fine and to tell his parents I would be billing them for all the above mentioned. I never heard from the kid again. I've had Luke 14 years now.

Good luck!!! All paws crossed here!!!