Why is it that when you go out of your way to help someone, do them favours and do a bit of chasing stuff for them, they then decide not to bother with you when you have arranged something because someone has turned up at their place and they don't have the bottle to say to them "I've got other plans, can you come round another day as I'm off out tonight" ?

Really pisses me off and feels like I've been shit on from a great height yet again

Guess you find out who your friends are the hard way sometimes