Am I wrong to still be upset and kinda spiteful?

Straight to the point. My friend said that now that I, and most of our girlfriends, have a boyfriend she is feeling neglected. I didn’t think that was true but I decided to give her prefernce anyway. One day she suggested that we go out, just the two of us. My boyfriend called a few hours later and he had made plans to take me out. I said I really can’t because I already made prior plans with my friend and it would be wrong to cancel because I wouldn’t want someone to blow me off for their boyfriend. He was a bit upset and disappointed but there was nothing I could do and what made it worse was that we wouldn’t be able to see each other for quite a while after that because we were both going to be busy. Anyway, on the day my friend planned to come pick me up so I got dressed and waited for her because I didn’t want her to wait for me. So she calls half an hour later than what she was supposed to come, to cancel without any explanation.

SO here it is, I have been upset (off-ish) with her for 3 days now because I could’ve been out with my boyfriend instead if she had to tell me earlier that she couldn’t make it. I also decided not to give her preference anymore. So. Am I wrong to still be upset and kinda spiteful? Because, I mean, I gave her a chance and she blew it. I felt as though I had been messed around. Guidance needed.