First, as a shop owner, I can tell you there is no such thing as an "LBS policy". Some shops are run well, most are not. Sad but true. Every case is different, and it sounds to me like there was a little communication dissonance between you and the appointed wrencher.
The MO at my shop is that until we know someone and their abilities, we probably over-explain a little. There is a difference between over-explaining something and talking down to someone.
We might have said something like:
"OK. I understand there is a drivetrain issue, and you believe it might involve the front derailleur. We will test ride your bike and pinpoint the problem. If it is, in fact a simple front derailleur adjustment, the charge is $10. If however, more is involved, we will call you and advise you on what it will take to fix the problem. In no event will the charge be over $10 unless you are called. BTW, if you bought your bike here, unless you crashed and bent something, there will be no charge for any minor adjustments."
I doubt that helps your current situation. I have had a lot of fun taking my bike to some of my "competitors" with something set slightly askew on purpose and been amused at how nobody (except one) found it. And I still can't believe so few shops can figure out how to adjust an STI triple front derailleur!
Good luck-and talk to the boss.