Are You There?... Really?

I have had several experiences of this. Friends that you've known for a long while who always claim to be there, but when you need them most they've disappeared.
I am always there for people when they need me. I have my cell phone on 24/7 and under my pillow at night so that it can wake me up when someone needs to talk. People always like to come to me for advice. I don't know why they come to me, but I'm there for them. I help them no matter how tired I am, or how early I have to wake up the next morning.
I guess I just don't understand why, when I need help or someone to talk to, no one is there to text me back or answer their phone. I guess it doesn't really matter does it?
I, for one, will go on helping people even if I never get help.
I'm not calling anyone specific out because I have a good many 'friends' that do this to me.
I just wanted to put this out there and vent a little bit, so no one get mad at me. Also if you ask me if it's you, even if it is, I will say "No". I don't want to hurt feelings. Those of you who are these 'friends' should know who you are anyways.