Call of marriage due to no feeling from

Dear Sir I got engaged with Girl choose by Family. I like her and fall for her, but week after our engagement she start behaving wrongly with me. Whatever I say she took it completely negative. Even if I just ask her to call me or talk to me she reacts negatively. She directly said to me she is not attached to me. I said it’s ok slowly you will fall too. But after that she starts behaving very rudely to me. She doesn’t care for my feelings towards her. If I asked her to meet or call, she talked rudely is it compulsory to meet? If I say meet for dinner on occasion, she reply she doesn’t want to eat so no need to come. I always open my heart to her but she doesn’t have any feeling for me even more she don’t respect me at all. After suffering for 2 months, I decide to stop talk to her, so she may realize but here also she don’t even bother I talk to her or not. So finally I involve my family and her family to look into matter. Girls Aunt and Mother Say someone did black magic on her that’s why she behaves like this. But I noticed it’s come from her basic nature only. Even on my birthday she called me in the evening 6.30 to wish me that also just very much casual like there is no relation between us. Finally I give up after so much mental harassment by her and decide to call off the marriage and ask to solve the matter by returning the gift. Now her uncle threaten us to come to their home if want to solve it and only gents should come. Before when we ask her mother to involve there uncle her mother always say no need them. Now her mother stays apart and put her uncle in between and now they just want we should go to their place so they can do something bad to us. Her uncle is a politician so we don’t want to involve any wrong case. We are very simple family and don’t want to go to court matter. I have our call records of our conversation and what’s app chat where she proven that she doesn’t have any feelings for me and talking very rudely. So please help me to get out from this without having additional trouble for me and my family. We just want they should return our ornaments given to girl during engagement and solve this matter peacefully.