Husband asking for a divorce without any reason

My sister got married in court 2017 without the consent of boy’s parents. The guy assured that he will convince his parents in a couple of months. He never took her to his house and she continued living at her own place. He met her occasionally in hotels and kept assuring that his parents will soon accept her. We tried to convince his parents all this while but his mother abused us all and threatened to kill my sister and was adamant that she will never accept my sister. She got pregnant with her first child and he forced her to abort the pregnancy stating the reason that this way he will never be able to convince his parents. She agreed and aborted. Two months after the abortion he sent a divorce deed and is now saying that he’s fed and he doesn’t want to continue this relationship. We have been asking for reasons but he is just saying that I’m not in a mood now. We have filed a case and mediation is going on.. they are still adamant that we do not want to carry on with relationship and they want us to opt for mutual separation. Mediator is also talking on the same lines. My sister is shattered and doesn’t want any money settlement. Is there a punishment for such kind of frauds??