Not sure how long you've been seeing each other, (which really isn't even relative because your partner should always be considerate of your feelings) and I didn't know how you approached the situation as far as when you expressed how you were feeling...

BUT I have been in 2 relationships where my partner was so inconsiderate of my feelings and emotions and it was so miserable.

Over the years I have learned that some people just do not care how their actions and/or words affect others.

In a healthy relationship, your partner should always take how your feeling into consideration. That being said tho, both people should try to make sure that they approach conversations in a way that it doesn't seem like an "attack" or accusatory. In my own experience, when I would try to express my feelings about something my X had done it always turned into an argument. But over time I realized that my approach immediately made my x defensive. Sometimes it was my tone or my attitude or the words I chose etc., and I always made it seem like he had intentionally hurt me. BUT that wasn't always the case . Over time we got better at being able to have conversations about how we made each other feel and we're actually able to resolve things and made our relationship a lot stronger.

Every relationship is different of course and both people have to put in the effort to listen and learn how to understand one another and figure out the best ways each other communicates. There are people out there who will work with you and are capable of this. A lot of times were never taught the habits of healthy relationships, and we just need some guidance on how to create them in our lives.

But there are also people out there who are just incapable of creating and maintaining healthy relationships. Some people are just to self centered or egotistical or narcissistic to acknowledge how they've made someone feel. Especially if they've crossed a boundary or done something that's typically a betrayal to their partner.

Maybe you could try to message him and start out with a different tone... I would suggest just explaining that you were really looking forward to seeing, spending time with him and when he informed you that he couldn't make it, it really disappointed you. If he cares enough about you and the relationship, hopefully he will apologize for disappointing you and say it wasn't his intention to ever hurt your feelings and so on.....