losing touch

Sometimes it's hard to keep up with friends all the time when they're spread across the country and beyond. But how hard is it to pick up the phone and say "I'm back in town. Wanna catch up?"...? This has happened to me today and I'm a little hurt and confused by the lack of communication. It may be that I've got it wrong. That the person in question may be on her way back to town, but not yet here. But I don't think so. If I'm wrong, I'll hold my hands up and apologise. But if I'm right, what happened to the call mentioned above? Why didn't I get that?

I don't like to think that I'm losing touch with a person, or they with me. Not after that person has been through a lot with you. But when this happens, isn't that the only explanation?