I'm confused when you say that the upper auger works fine but the lower won't turn either direction.
The upper portion of the agitator which is referred to as the "auger" is driven by the lower portion of the agitator. The auger is designed to ratchet one direction to pull the clothes down under the surface. It can be rotated anytime, when off or when running.
The lower portion would have to be moving back in forth for the upper auger to work when it's running. If the washer is
running you will
be able to rotate the lower agitator portion either direction, however you will be able to rotate the upper auger portion when the washer is off or on which is normal. If the washer motor is running and there is no agitation action or any spin action during spin then most likely the washer has a broken motor coupler.
The motor coupler is the component that connects the drive motor to the transmission, and when it breaks it will not agitate or spin. It will however still drain water out.
I recommend calling a service technician to diagnose and repair your washer.