Guy promised to marry but now refusing, what action can i take on him?

i am cs engr we r muslim, we both r in 7 years of relationship and madly in love , but he was adopted by his mom , so now she is opposing our marriage, she does not believe me as we are in long distance relationship, and my younger brother does lot a torture when it comes to finance issues i pay his debts and so she think i wod in helping him lie her and cheat her son, i am 1 month pregnant , the guy has got engaged to someone else , and he himself told me, and said i cant break that as mom brought me up gave me name,prestige clothes everything. so i will marry u and keep u in Mumbai and i ill marry mom choice girl and stay there .i dont think this is right.we tried to tell her mom about pregnancy, still she denies and say in a day many ppl sleep with each other,do they marry no..! he promised me in front of all his khandaan and mine now i dont wish to share him but wod teach a lesson ,if forced so is there any law for cheating and breaking and cheating i have a message recording