What would ypou say to a colleague at work who has just destroyed your memo?

that took two hours to design and type? She has simply lost all the information, no trace anywhere in computer, nothing left. I asked her to do re-type it, she refused and asked me 'where did you put that memo?!?' Like I had lost it. Then she refused to have anything else to do with this issue. I asked once in a polite way.. what to do next?