Query related divorce and maintenance

Our marriage was held in 2009..Till now nothing gone smooth in our relationship but I was and am trying my level best to maintain it.we also have one son of age 7 years.My wife used to move her parental home n lived there for long time.The same thing happened in August 2015 .She gone to her parental home by saying to meet her parents and then as usual she didn't come back .After than me and my parents tried so many times to taken her back and at last in June 2016 she came back and after that we all family gone 4 small trip and after coming back from trip she said she wants to go to there parental home to meet them ..I said ok and leave her to her parental house .She come back after 4 days with her mother and after few minutes again started fighting n left the home again..Til now she is living with her parents but in the whole time she had left the son with me (Aug 2015-june 2016) (last week of June 2016 - till now).In the mean time she complained case in women cell by complaining all false cases on me and my parents and my sister .She complaint that I never taken her for any outings ,not bought anything for her but I have pictures with me for every year short trips and so many articles.She complaint against my parents and sister for I'll behavior. In women cell because of her family approaches of high level,no one listen us.Several meetings done but no result come.She said she will neither give divorce nor live with me..either she spoil me by harassing me n my parents.Now she had filed a case for maintenance u/s 125 . I want to know this how can I will get divorce from her as me and my family is now so much harassed from her?? and how much maintenance I have to given to her as my monthly salary is 50,000 and my son too is with me and his complete responsibility is on me. Plz help me and sought me some way so that I can get rid from her and also get my son custody. Please help .