Fillet extruded curve for pendant?

Hi, I am attaching my file. I have a shape, a closed planar curve, that I extruded. Now I want to fillet the shape so I have rounded edges. But when I used the fillet surface command it doesn’t really work. What am I doing wrong. ignore the design in the middle for now. Thanks!joe weed.3dm (3.9 MB)

Here’s a link to a good video tutorial that will help you understand how to take best advantage of FilletEdge:

Thank you. Susan