What should i do about my ''friends''? confront them or act like nothings happened?

i dont have alot of friends,only about 3..all these girls have been friends for a little longer than i have been friends with them and they are really close and rarely include me in there plans..i try ALOT to get them to do stuff with me but theyll say oh ill calll you tomorrow and then they wont call me tomorrow and im waiting by my phone to see if itll ring..its so pathetic that the highlights of my summer is food shopping wih my mom or something like that...i can call them and ask to go shopping and theyll say call you tmorrow and ill say ok and the next morning they wont call me..ill text them and say were supposed to leave in 10 minutes are you comng or not? i know theyll receive the text in that time slot and theyll just ignore it..i know that they like me because when we do hang out theyll always include me and stuff..i know when someone doesnt like me and they do..but they just wont include me..i dont know what to do because sitting at hme everyday is really starting to get boring...if i confront them i dont want to insult them and have them not be my friends because then il have absolutely no one..when school starts ill work on making new friends ...what should i do for right now?