Legal action should be taken against groom for cancel marriage

What legal action and complaints should be filed against the groom when engagement is performed and he cancelled the marriage due to his love affair with other girl and cheated us. This was the arrange marriage,and the groom was having affair with other girl and groom's parents was aware of his affair even though they made an attempt to approach us for marriage and didn't told us about such issue about groom's affair. The engagement was performed in front of about 150 people in a hotel and after few months marriage date was also fixed and everything was well and good and all the preparation like hall booking,tent, decoration,catering,band baja and also the reservation of train was done.The invitation card of wedding was also distributed to all. But suddenly 12days before the wedding groom's lover told us that they were in a relationship since 5years and grooms parents also knows about this and they cheated on us and cancelled the marriage. The bride is suffering from the mental harrashment and affected reputation,because of being cheated by groom and his parents.What criminal or legal action should be taken againt them.