No.
Call a few times on or just before the half hour.Leave a text as Irish Belle says , saying it's okay to text back .If you know some respond to PMs try that, if they can see some info about you.Ring in the morning or lunchtime perhaps , rather than evening when they may be busy .If you make an appointment hours before, ask how to confirm it .
If no response after a couple of well spaced calls, leave it, maybe try another day.