What had happened in aunt's house?

The trio that went to stop the marriage explained the reasons for the same:

Myself and Prakash went to Papanasam to pick up Ravi and Mangalam. Their father blessed them for success saying that they had not harmed anybody and so, God would surely help them. I noticed a change in the behavior of both Vaithy uncle and aunty. After Mangalam’s return to Papanasam from Chennai, they both were always crying, feeling helpless. But now, they looked firm and courageous. I understood that they had decided on a firm course of action and that they were clear about the same.

Initially I hesitated to accompany Ravi when he said that he was going to Chennai to stop the marriage. But I decided to accompany him as I was sure that whatever Ravi and Mangalam did, there would be justice. I was sure that their aunty in Chennai and her family must have done some serious harm to Mangalam. Both Vaithy maama and maami believed in pava punyam. If they approved of Ravi’s action, then, what I guessed should be correct, I thought.

We went by road to Chennai in Prakash’s ambassador car. Prakash, while driving, asked, “Are we going to the marriage hall tonight itself or tomorrow morning?” -“It is enough if we go there before muhurtham tomorrow morning. Nobody should come to know that we are in Chennai. We should enter the hall to their shock and finish our job without giving them time even to think,” Ravi replied. “Mohan, we could understand your trust in us when you readily agreed to accompany us even without asking for any explanation. But you should fully know about everything that happened in Chennai, only then you can support us wholeheartedly,” Ravi told me. Mangalam started crying and Ravi consoled her telling that the next day, it would be the aunty, her daughter and Bala who would be crying.

Mangalam started narrating. “Mohan, you know well how Lakshmi aunty got me at her place through her tears. She created scenes when we arrived at her place. She behaved very well until my parents left for Papanasam. While leaving, my father told me to take care of Lakshmi aunty and said that after aunty recovered from her illness, he would come again to settle my marriage with Bala. Aunty’s husband was very detached and would not talk much. After my arrival, aunty terminated her cook and servant maid. I used to cook so many items for aunty, Bala and Janaki (aunty’s daughter) who would visit her mother on four days in a week. But I didn’t bother about the burden of work there since I believed that I was going to be the daughter-in-law of the house. But Janaki was a big source of problem to me. She wouldn’t relish if I wore a good sari, if I sit close to her mother or listen to radio. Then I took care not to irritate her. Bala was always irritable and would never answer me. One day aunty scolded me saying that I should make Bala eat and take care of him since I was going to be his wife in future. I was always afraid that aunty might mistake me if I spoke to Bala. But when aunty scolded me that I was not looking after Bala properly, I shed my fear and insisted to Bala on having his breakfast and coffee. Like this, I started taking care of his matters. In course of time, Bala became friendly with me and started showing affection.”

Ravi continued, “The closeness between the two grew due to the encouragement of Lakshmi aunty. One day, they crossed the limit and Mangalam gave herself fully to Bala because of her firm belief that any way she was going to be his wife.”

Mangalam continued, “It was a Sunday. I was cleaning the vessels. Aunty asked her husband to get Bala’s horoscope from the almirah. On hearing this, I came rushing believing that they were talking about my marriage with Bala. But on seeing me aunty said, “Mangalam, bring kumkum. Contractor Chandran is coming here today to exchange horoscopes. His daughter is also a civil engineer. They are very rich people.” I felt like swooning. I rushed to Bala who was upstairs. But he coolly said, “Yeah, I am going to marry Chandran’s daughter only. You are a country brute, how can I marry you? Whatever happened between us was only a time pass. I’ll not reveal it to any one, you also don’t. I’ll fix up a match for you from among my friends circle.”

Mangalam continued, “Then, I went to aunty and told her the truth. She was very annoyed with me and put all the blame on me. Then, she coolly ordered me to prepare some sweet before the girl’s father arrived. At this juncture I asked Ravi to talk to them”

What happened when Ravi spoke to them? What happened to Bala’s marriage?