well revenge isn't the best venture, so be sure you're doing this for the right reason. i tend to say wait two weeks before casting a curse/hex because your judgement is clouded with anger.
i don't know the spell, so i can't say if it's a working spell or not, but if you can focus and visualize all your energy/anger towards this person and getting your revenge, it should work. be warned you might feel some negative effects as a result. even if this spell is justified, you will have negative energy surrounding you because of the nature of the spell.