Hey, im currently designing a Iphone 4 case and I need some help.

Im currently trying to cut some spaces for the ports, using the extrude cut feature. However, the shape im trying to cut spreads across 3 different planes, and when I use extrude cut it doesn't let me cut it beacuse it does spans across 3 different planes. So my question is how do I extrude cut across 3 different planes if at all?

Thanks