These girls I met in high school keep ditching me. Why?

I mean they seem like they love having me around but I hear them taking about weekend plans behind my back. They never call to invite me or anything. Well they did. My older siblings warned me about them and they said they aren’t my friends. They don’t seem like they care about me at all and abandoned me. They don’t know what they’re talking about! Even my dad said the same thing. The girls wanna talk to me again.
I’m still upset with them for abandoning me at the restaurant and said they had to make a “phone call”. I found out they went to a party. This was last year.