Did I just mix up the white wires. After wiring and hanging my ceiling fan, I noticed when the switch is off, there is power to the light and fan and when the switch is on power is only to the light. There were 3 bundled black wires from the ceiling, two whites bundled, and one single white, as well as the ground. I connected the black(fan) to the blacks, the black/white(fan) to the white(pair) and the white(fan) to the single white on the ceiling. Do I just reverse the black/white and the white? Also can you replace a single switch with one that can control the fan and light independently?

Thanks

Ok, when the switch is off, do the fan and light work as they should?

Assuming the colors are correct, all the blacks should connect the fan black and blue, and all the whites should connect the fan white. But you MAY have a white that is mismarked.

Ceiling fan wiring - Ceiling Fans N More