I never turn work away, as you never know whats around the corner.
I just sub-contract out, and check that their levels are up to scratch, and top up the standards if needed.
Know what you mean though, I have had 2 bolier fitters not turn up for pre-arranged appointments to discuss my requirments.
When I rang them , they said that they were busy, I politely said, well don't make an appointment with me then!