like anything complicated. Is the starter gear supposed to move up on
the shaft as it spins? I don't get it!!! I am mad as heck.

Who are you mad at? Yourself? (I hope) for not knowing how to maintain
or work on a boat.
It sounds like the work you had done had nothing to do with starter
motor maintenance, so you can't be blaming the repair shop. Or do you
just lose your temper every time something doesn't work? In that case
please see a shrink.