3D surfc issue, contours not showing up in the correct place.

My code is...

surfc(X,y,Z);
hold on
axis([-2 2 -0.5 0.5 -1 0]);
surfc(X,-y,Z);

I'm trying to have my contours show up at Z = -1, but only the contour for 'surfc(X,-y,Z)' is doing that, the contour for 'surfc(X,y,Z)' is showing up at Z = -0.5. Is there a fix for this?

...

... I was able to find a workaround for this but still unable to solve it. I just made a surf(X,y,Z); at the start so it looks like this.

surf(X,y,Z)
hold on
axis([-2 2 -0.5 0.5 -1 0]);
surfc(X,y,Z);
surfc(X,-y,Z);

This produced the desired result, however I don't consider it a solution, more of a workaround. Is there a way to achieve this result without using this workaround?