I have been pretty fortunate for the most part.

I did have one shop sit on my parts
for a few weeks, and then they called me saying a bigger job came in the door that we have to prioritize
in front of yours, so we won't be able to do your job. At all.

That was enough, but things turned bizarre when they then offered to take my parts somewhere else (of their choosing,
somewhere that I have no idea if they're any good or totally suck), to 'help me out'.
I had to wonder, what does this other place that I know nothing about kick back to them?
I declined, went and picked up the stuff and started over.