I've rolled my modeling chocolate out on a slightly dusted surface (top & bottom) of cocoa. I've also dusted the plastic mold.  When pressing the  numbers mold into the chocolate the mold will not release the numbers.    All I've managed to do is make a huge mess.   Any ideas what I can try next?  Thanks.

put the whole thing in the freezer for 10 minutes.  

Thank you leah_s, I've tried that, I've tried freezing the modeling chocolate before cutting, also oiling the mold & nothing has worked.  I have never had this problem before.