You can't make people change. You can't wait around hoping that one day, they'll have this epiphany and realize they were wrong all along. That they were selfish. That they lost something important and that they'll pick up the phone and call you like they used to.
The only way people can change is if they realize their own faults in their own time and make the strongest of efforts to fix it. The odds of this happening are so slim. That doesn't mean it can't happen....it just means that it usually won't.
And it hurts. Knowing that no matter what you do, what you think, what you hope...
is of no avail. The best thing you can do is realize that putting so much effort into "fixing" someone else is only going to lead to losing sight of yourself. Then you'll just end up being the one in dire need of repair.
You have to just let go. And wait for someone who is willing to meet you halfway.