Getting the bad part of a bargain. It comes from the song: "She Got the Goldmine (I Got the Shaft)" written by Jerry Reed.
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
Why'd you make that trade, you got the shaft!