I've learnt to contain my frustration and anger. Like many have said, I believe also they thrive on it. Within their sad little existence.
I always ask them to reconfirm an hour before by phone call. And to txt when 10/15 mins away.
I only finish preparing once I get that txt saying on way.
Usually time wasters give up on these hurdles. And if they still turn out to be a time waster I don't chase them up, I wait in 15 minutes. Stay gleamed up for half an hour. And then remind myself to keep calm and mark their name and number with a record of what they did. I don't block either.
Unless their rude and insulting and clearly a TW.
Real life sometimes happens. I've once missed a dentist appointment because a boyfriend was causing drama, or missed a beauty appointment because work ran over.
So if they get in touch embarrassed (which some do). I say, not to worry I got taken out for lunch or dinner instead. And if you'd like to re book a deposit needs to be sent.
At end of the day we don't know if wife suddenly turned up and caused havoc with their schedule. Or their child did. Or work and they had to hide their phone.