Boy Refuses To Marry After Engagement

A boy got engaged and received Rs. 20 lakh as dowry via bank account. Later on, he found that he cannot marry the girl. But he could not refuse directly since the girl's family could file a case of cheating and breach of promise against him. So he decided to postpone marriage for an unlimited time giving an excuse for higher education. He did this so that the girl's family may refuse on its own and he will return their money. Can the girl's family threaten him of any legal action and force him to marry according to them. What can be the consequences of this?