Mishka 3 Threadless End with CZ

Well I was SO excited to get this and finally Change out my jewelry. I received it and it was so beautiful I chose this because I have 3 girls and wanted the three stones. I already have a back and when I went to put it in it did not fit properly in the backing and it came out and fell down my sink. I took my entire sink apart and still can’t find it. I have been sick over it 😢