How to file in for divorce within 1 year of marriage

Hi, m Muslim n I got married on 22nd may 2017. After a month my wife went off to her parents for function. During ph call she admitted various times that before marriage she ws in relationship with a guy wherby in so she gt pregnant twice n aborted same. I have call recording for same in which she admitted details of her past relationships. However she got back to me after a week. I asked her for divorce , she denied n warned me if I expose her past relationships she ll commit sucide n make make false case of dowry n physical violence. I haven't taken a single rupee or anything of marriage as we r against dowry. Again on 26th aug 2017 she got to her parents n living there till present. I want divorce bt they r nt agree for it. Thereby kindly plz show me the right path to get divorce n save me n my family.