This is a spell so the people you are bound to karmically don't continue to play the same detrimental roles in your further incarnations. On parchment or some other nice quality paper, write in red ink (dragon's blood ink, bat's blood would be great too):

(Name) I declare our contract broken.

You no longer have power over me.

Never again will I be your servant, in this life or any other.

(you can use your own words, go into detail about how you feel you've been wronged manipulated, whatever.)

Sign your name, burn it with a black candle. Get rid of the ashes.