I'm going to yell at a dental receptionist for canceling my appointment after waiting for so long
What if she made a mistake on your scheduling?
This isn't the first time this has happened.
You are upset over some kind of appointment cancellation which can be frustrating, but yelling is something that makes everyone feel bad. In order to confront someone you should be calm and then they will fix the problem faster for you. Screaming only makes mush out of someone's mind and makes them more confused.
I don't need you to lecture me and I don't care if I yell or not. You won't put that on your blog anyways.
You should be kind to the person scheduling your appointments. There are other reasons like the doctor being sick that there might be a cancelation or the weather. If you are rude she could "forget" again.