Physical assault by Residents welfare association employees

Employees of welfare association of a popular apartment complex in Gurgaon physically assaulted me and my 62 year old father. All events are captured in CCTV. Police was called the same day but a compromise was reached when Board members of the society assured us after watching the CCTV footage, that appropriate action will be taken against the employees. Next day all blame is put on us for 'starting' violence. 16 people, including witnesses of this event, as well as people who've experienced misbehavior from the same employees in question, wrote to Management to release the CCTV footage, which they did not. The main employee responsible for the violence has past criminal record. We have access to his apology letter to one of the residents, that he wrote after getting detained by the police. This event happened only last year. He was expelled by the management then, but was strangely put back to work a while later. Management notoriously defends this employee for some reason.