Thank you for your answers! Yes I'm thinking the passport may have been lost or stolen and I will talk to my embassy on Monday. She wasn't able to produce a photo of my passport when asked recently.
And yes I can meet her anytime, but she won't give any reliable info. Good point about the registered letter.
I'm not sure what a legal action would look like since I'm not even supposed to give my passport to a private person in the first place.