That’s really horrible. Do you have sketches of the design? Maybe show those to people in future. I always keep a working record of my designs so when showing people they understand that every photo I am showing them ‘really’ is mine! I also refuse to ‘copy’ designs.
Hope you track them down and be safe in the knowledge that even if they do post your photos they will never be able to recreate it like you did :)
Simply Alpa