AC/Heater problem

Problem: Hot air is always blowing from bottem vents even when AC is on. Cold air will blow from top vents while hot air blows from bottem.

Awhile back I removed the AC/Heater control box under the radio. In the process I guess i pulled to hard on some cables connecting the control knobs to the vents (at least this is what the dealership told me). Also when I set the knob to blow from both top and bottem vents air blows thru both properly except for the fact hot air blows from the bottem at all times. But when I turn the knob to blow on just the top vents the air comes out the top of the dash where the defrost air comes from and not the vents that blow towads the cabin.

Its been along time since I did this and just never felt like taken care of it. Now that I want to go ahead and fix it I dont really remember to much about it and dont really know how the control box works. Does it sound like i crossed some cables and thats why the air blows out the wrong vents? Is what the dealership said sound correct about pulling the vent open to allow hot air to constantly come out?

Anyone know if this is something i can fix by taking the dash apart and accessing all the cables and vents?

Thanks for any help.