If I read things correctly, both shuttle switches have been replaced and you confirmed that they work in diagnostics, correct?
If true, are they being toggled by the shuttle when going in/out? There is a bracked on the back side of the shuttle casting that swings to make contact with the switches. Sometimes this can become loose causing the bracket to not trigger the switch. It is held in place by a set screw to the motor shaft.
If this does not fix the problem, I would call your dealer back out and make sure they fix it compeltely, because it sounds like you need it back up and running in a timely manner. Maybe request a different tech.