Excessive VBOs and no batching while instantiating prefabs

I'm creating a program in Unity 4 that requires me to instantiate large amounts of objects which represent vertices from an external model but I'm having problems with performance. In the image below I've provided two stat windows, the top is directly from that image while the second is from the same scene with the instantiations being frustum culled.

The scene as a whole contains a floor which is just a cube, a directional light, the sphere in the foreground and those objects in the distance (these are set as static after instantiation). I'm aware that unity has some built in batching capabilities to reduce draw calls but they just don't seem to be working as you can see from the 2082 draw calls (there are roughly 1200 of those instantiations). Does anybody know what I'm doing wrong?

EDIT: I should also note that these instantiations can be destroyed and moved individually at run-time therefore the mesh combine unity script isn't an option as far I'm aware.