Do the following things:
1. If you love her then become an insane lover and don't be afraid of consequences.
2. Take help of media and do publish it your story of ditch along with evidences.
3. Create a scene during the time of her marriage,hire a good projector and make all the snaps digital and project it on the stage.
Two things will happen , her would be husband will never marry her and you will also loose her humesa k liye.
Lesson: Love can't be confined or forced,if she want's to go let her go if she returns back to you ,then she was truely made for you.....
Kitna bhi kar lo kuch haasil nai hoga.Instead of that you would have left her and taught a lesson by becoming richer and marry a more trustworthy girl than her infront of her nose to teach exact lesson what she had done to you.
Regards,
A sufferer.....