Wait for a service estimate?

After no contact from the shop for 24 hours, I decided to call. The service manager let me know that they didn't get to the boat yet, but would get to it at 10am or so the next day and let me have an estimate by that afternoon. As you can probably tell, the afternoon came and we didn't get a phone call. Anyone else have this happen to them? I know it depends on how many boats are in front of yours, but do they at least asses your boat and then get back to the ones in front of you? Or do you have to wait until they're completely done servicing the other boats before they can give you an estimate? Not getting a phone call back after someone says they'll call is a pet-peeve of mine, so I might just be being difficult. I call people back at work all the time whether I want to or not, even if it's just to say I'm still working on it. Am I crazy for wanting the same in return? Any advice? There are plenty of other service shops in Austin I could take it to if necessary.