Learning, I'm not sure I understand

You had a T appointment
you arrived maybe 15 minutes late
T was not there (????)
so you left (I guess?)
and later emailed, saying I'm sorry I was late
and T has not responded

Is that the way it happened? If so, I too would think that yr T should respond; but then again I wouldn't hesitate to ping again and say, ahem, I said I was sorry for being late, but where were you? I came and you were not there?

just speaking for my T, I would absolutely expect her to hold that hour for me, even if traffic or something held me up for 15 minutes or even more. if I am truly a no show I will be charged for the hour, and I know that, but responsibility cuts both ways.

for you