Getting the bad part of a bargain. It comes from the song: "She Got the Goldmine (I Got the Shaft)" written by Jerry Reed.
SNIPPET:
She got the goldmine (She got the goldmine)
I got the shaft (I got the shaft)
They split it right down the middle
And then they give her the better half
Well, it all sounds sorta funny But it hurts too much to laugh
She got the goldmine, I got the shaft
When you get screwed over, often by someone who's name begins with the letter "A". normally said when the screwing over happens to you, but if it happens to a friend it is permissable to say as well
1)Bill: ya josh got dumped the other day
Jack: A-Shaft!
2)ya he stole my seat the other day in carpool, it was a major A-Shaft. and it was after i called shotgun too!