Ah that's why, you have the Core2Duo model. They're very, very picky with 16GB RAM. You frequently can't go beyond 8GB RAM on them, if at all. Only the 2011s or later can reliably go beyond 8GB RAM.
Also the RAM you ordered is 1333MHz; it should be 1066MHz on your model (2x4GB SODIMM).
Anyway, best thing to do is replace the original RAM and reinstall OS X from there. Should work fine. Then return your RAM and order the 1066/2x4. 🙂