love problem . parents threatening the girl .

Respected sir/madam i am in love with a girl since 2008 she is 27 now and i am also 27 years old . both of our parents know about our relation from begining and agreed for marriage too . on december 24th 2015 we both had small argument . that was known to the girl parents and tried to contact me . i was totally upset and did not answer any calls for 3 days . the next day when i called them , they said it was all over and do not come in their daughters life again . my girl friend was threatened not to talk to me and forget me . she called one of my friends and talked to him on phone . she cried and said " my parents asking me to forget him and if i marry him they are saying that they will commit suicide " it was recorded on phone . at that time they house arrested the girl for 15 days and did not allow her to go to job and didnt allow to talk to me . 24th december 2014 was the last time i talked to her . please suggest me how to fight legally to get her back . thank u .