What you need:
Experience with astral projection

Meditate and leap to the astral level, find the victim who has wronged you. Place a circle around them, quickly construct this circle into a circular cage, with a roof on top. Place onto the roof a sigil that you have beforehand made that will represent you, place magick into the sigil in some way (the astral sigil not the real one), any way is fine. Now instruct the person that the cage is real and unbreakable and that they cannot escape it unless you specifically let them out. Also instruct them that as long as they are in this cage, they must obey you completely. Now do as you please. And enjoy your revenge. But be prepared, no one knows what might come of their actions, whether good or bad, this might help or hinder you, as any spell might.

P.S. You can use this spell to cause this person to lose his apartment, or partner, or to make their grades drop, or to make them do something to get fired from their job. The possibilities are endless.