Don't give up on them. Maybe give it a weekend or two.
One week just send out a text and invite them all out to see a movie, play video games at your place, hang out, go to a party, out for a drink, whatever it is that you guys are into and makes you all friends.
Just let them know what you're doing one weekend, then tell them they're free to join you in whatever it is. If that doesn't do it, then just keep on doing what you do. Invite them to join you when you're doing something fun. But keep on meeting new people as well
...Or you can become an Avenger :| (Nah, don't base your life off of a manga character, especially the character that things don't work out for!)