Wife took the kid to her parents house and not coming home

I had a arrange marriage approx 5yrs back i am 33 years old. Since the starting my wife always found reasons to fight and go to her parents house. she never liked my mother even though they made a separate floor on existing house just for our happiness and privacy. she fought and fought and we started staying separately ie away from my old parents in another city. but still she found reason every month to fight and go to her parents house. every time its the same routine she fights and calls her dad and he comes and pick her up. i have a son who is 4yrs of age because of him i g everytime and say sorry and get her back. in fights hits and scratches me also. she abuses and drive me nuts. i get up and do everything for my son right from making him ready for school to making him sleep at night. i got him admission done alone she didnt even bother to buy books for him. she dosent care for his routine or even hygiene. i wonder how she must be doing there. she abuses him and hits him also. i am from a educated family and scared and lost as what to do. now its been more than a month she has gone to her parents house and i miss my son like anything. her parents came and accused my parents for what not. they harass us and everytime wants me to beg and plead. i am tiered of living in this relationship. indian law will always favor women i dont know what to do. please help. talking and solving has not helped in past. she finds one reason or other. please help.