that doctors, dentists, plumbers or what have you, tend to believe that only their time is precious. Maybe there should be a different approach:
Dial the doctor's office. Tell the "girl" that you would like to see the doctor at 2:30 on Thurday, October 9th and that he could call back to confirm.
Use the same technique for the plumber: "My kitchen sink is leaking and I would like to have it fixed at once — can you come within the next 30 minutes? You can't? Okay, then I'll have to call another plumber. Thank you."
OR: Perhaps the eye doctor: "I would like to have an eye check up on Friday or Saturday of this week. Can you see me? Ok, then I'll call someone else. But I will put you down for another year, possibly, for my next check up. Mark your calendar, my name is . . ."
Perhaps for the painter: "I have 3 rooms that need painting. If you will drop by before the week is over, I may have time to show you what needs to be done. You may call first if you like, to give me a time. Just leave a message on my answering machine so that I will be at home when you choose to come for a briefing and possibly we can make some arrangement for the job."