said by LongWait :
They promised numerous times to call back in "30 mins" starting at 9PM last night. (But still no call back after ~19 hours and counting)
That's standard business math. If the air conditioner repair guy says he's 15 minutes away, expect him in half an hour. If you get an appointment window from 10 AM - 12 PM, expect them at 12:15. If the nurse says the doctor "will be right in", you'll be waiting another 20+ minutes.
I'd much rather have honesty than misguided optimism or flat-out lies. If I know I have to wait an hour, I can do something else in the meantime. Don't keep telling me it's almost my turn and waste my time.