Unfortunately, this happens more frequently than we know. Agree with what others have said, contact Facebook ASAP so they can deal with this issue.
I have a professional cake decorator friend, been in business 40+ years. A newbie that opened in her area actually took pics off my friends cake website and and passed them off as her own. A savvy customer who was having a consult with my friend recognized the photo the “other decorator” had shown her. Sorry to say when it comes to business and money, some people will stoop pretty low.
Creativity is God's gift to us. Using our creativity is our gift back to God. Clarky's Cakes 😎