Gold320

Hey all , I just picked up my c320 2002 from a mechanic. And he said the the reason my battery is dead is because the blower for the ac keep running ( hours after car was shut off and keys out ). He discovered that when he left the setting on full blast and turned the car off the motor didn’t run , but when he left it on setting one or two ( not full blast ) The blower would continually run until the battery is dead .. my question is should I change the regulator or blower itself or does the control panel part need to be changed ? Also when my ac setting is on I don’t get any airflow to the vents only to my feet. When I change it to vents or top nothing changes. It continues to blow on my feet .. so maybe it is the control panel ... please help .. any input is appreciated!!