I made a FBCT but it won't come off of the wax paper. Why not, what did I do wrong, is there anything I can do? I let it freeze for about 4 hours.

How thick was your piece? Sometimes if it is too thin it won't come off cause it thaws too quick.

You can try placing the transfer on top of the cake, leaving the wax paper on it then put both in the freezer for a little bit before removing the wax paper.

Here's a FBCT tutorial that might help.

http://cakecentral.com/article12-How-To-Create-a-Frozen-Buttercream-Transfer.html

Also, if you have "hot hands" like me, the second you touch a FBCT to press it onto your cake it will thaw. I found that what works for me is using a fondant smoother to press the FBCT into the icing before removing the wax paper.