My switch controls my both top and bottom on my receptacle. I only have 1 cable coming into the box for the switch it is 14/2 or black(hot) white(nuetral) and a ground. I too want to install a fan and light combo. When I open the switch box the the ground was not connected. Now here's where it gets interesting. My father in law installed the fan combo with 4/2 and basically wired the fan in the same spot that the original wires for the receptacle are install also. When the fan is turned on the receptacle no longer is hot. When the fan is turned off the receptacle is hot but the fan is now not. Any help would be appreciated.
I don't think you have a neutral in the switch box. The original cable for the receptacle had only a hot and a switched hot. The new cable went directly to the fan and had no neutral. Both cables had a ground and I can only assume that somehow the ground was being used as a neutral. The fan could work, but the gnd is not supposed to be carrying current.
Is the wiring Romex (NM) or is it in conduit? If in conduit you could pull another wire from the receptacle to have a neutral in the switch box, and then you would add another wire going to the fan.