I'm so sorry. I'm not sure what to say about grieving. Do you have any pictures? Maybe you could write a remembrance and have a little service, maybe with some friends?

I know you are not alone in this type of sad situation. My sister and I had a mom cat and four kittens. My mother told us we each could pick out one kitten for our own, so we did. The other two, she said, would be given away. And they disappeared. But one morning we got up, after we had gotten used to our kitties, and the mom cat and my sis's cat were gone. For years we were led to believe that they just ran away, and my sister was crushed that her kitty had left her. Years later we found out that my parents had taken the cats and just dumped them out. So, I can understand how you feel, except they kept my cat---who knows why.