Owner refusing to return security deposit

Hello all, I am a resident of Gurgaon. Me and my friends (4 of us) were occupying a 4 BHK. The rent agreement was originally made in the month of Aug, 2019. However, me ( Ms. P) replaced a girl in Jan, 2020 and my friend (Ms. S) replaced another tenant in the month of March. We wanted to get a new agreement made / get ammendment on existing one with new names. But due to Covid-19, we couldn't get it done. The details of our occupancy was communicate to the owner and there are whatsapp chats to prove the same. Typically, when we replace a tenant, we transfer the security deposit to her. This way she gets her money back without bothering the owner. The tenants in such cases, only share the owners contact details after getting her full security deposit. There's no way to asses the damage at the time of moving in and reporting it. We all were paying full rent till Jun, 2020 and have electronic bank transfer receipts to prove it. But on 9th Jun, we all decided to vacate the flat and have owner ntoice. The existing rent agreement was also ending in Jun, 2020. We all vacated the flat by 30th Jun, 2020. We had originally agreed to a notice period of 15th Jul, 2020. Since the owner stays in Bangalore, he had sent over his manager to check for damages in the house. On the day we all vacated the flat and handed over the keys, no damage was reported. A week later, owner complained about damages and is now refusing to return money. He mentioned he will return a small amount to me and my friend Ms. K, because we had good relationship with the owner and we were the ones who had maintained our room as well as the flat. We also kept him in loop in case anything happened at house. He always recajed out to me in case he was having issues with other tenants ans wnated me to intervene and reoslve the matter. Not only that, while living there we were bearing charges of all small repairs and damages. It's been more than 30 days since we vacated the flat and even after constant follow-up, we haven't got an estimate from the owner on the damages. I would like to know in absence of a lease agreement, can I legally ask him to return my entire security deposit? And also failing to report an estimate on damages post 30 days of vacating the premises? Also the damages were reported a week later. I'd like to know my options before taking any hard action on him. Thanks! Appreciate your advice and your help! Regards, Ms. P