Why hang out with people who have lied to you repeatedly? If they keep making up excuses to not see you or don't even return your e-mails, then I would take a hint and leave them alone.
I had a similar experience last year with someone. Of course, I've tried to figure out what I did wrong, but I can't be sure unless that person re-establish communication with me. It hurt but I decided to move on with my life.