["Last week I made plans with a friend of mine I had not seen in a long time. But on the morning of the day, my friend said they couldn't make it! I was so really mad.", 'I hate when that happens.  It makes you wonder if they are really your friend or not.', 'Yea right. I was so upset that I considered ending the friendship with them.']
I know how you feel.  Try not to get too mad, maybe he had a good reason and didn't want to share it.
Last week I made plans with a friend of mine I had not seen in a long time. But on the morning of the day, my friend said they couldn't make it! I was so really mad.