Did I make a mistake by sending this message?

I'm 16 and so is my "best friend". She has a bf she's been dating for 5 months and won't shut up about him whenever we hang out or talk on the phone. Also, when they're together, they show WAY too much PDA. I don't have a bf, and I know she's rubbing it in my face. She's also lied about some guys liking me, and she should know that I'm not dumb enough to keep believing her. For my 16th birthday party, I had to call her the day of it to see if she could come. She said she couldn't cuz her "dad wouldn't let her". Later I called again to ask if she knew if anyone else was coming, and she said no. Then she said she had to get off the phone cuz she had a date with her bf! Later I sent her a message on facebook asking if she was lying about why she couldn't come to my party and that I wish she told me sooner. She hasn't been online for a week, so she hasn't seen it yet. Today my mom and I saw her at the mall, and she came up to me and gave me a big hug and asked how my party was, but I don't think she even knew if was for my birthday! I got her a present for hers, and she just blew off my party for her stupid boyfriend, and lied about it. She seemed sooo happy to see me at the mall, but something about her was fake. Did I make a mistake or did I do the right thing???