Long standing Dispute with User Car dealer

I am writing to share my recent experience with a used car dealer and seek your advice on how to navigate this challenging situation. On 11th February 2023, I went to purchase a Hyundai Verna EX 2018 (2nd owner, diesel) from a dealership called MY CARS in Chennai. The cost was 6.61 Lakhs, and I was assured by their associate, Bhavani, that the car was in impeccable condition. To back this up, i have video evidence of a successful test drive on january and audio recordings of Bhavani's assurances that the car only required an oil service. So i went to chennai for taking the car However, things took a frustrating turn as soon as I drove the car off their lot. The car experienced multiple issues and even broke down. I immediately returned the car to the dealership, hoping for a quick resolution. Despite their attempts, the problems persisted and I faced continuous inconveniences which includes oil leak from engine, spoke from injectors. After numerous back-and-forth conversations and several visits he also gave some temporary replacement cars for 2 months (one had odo tampered, as we verified with service center) so again he took them away also, and finally on August 1st week the owner of MY CARS, Mr. Akbar Hussain, acknowledged the issues and agreed to refund 4 Lakhs as part of the initial payment. He assured me that the remaining amount would be returned within a week. To my dismay, the situation went from bad to worse when the 4 Lakhs refund check was returned due to a "drawer signature differs" issue. This entire ordeal has taken a heavy toll on me, both financially and mentally. As it involves my hard-earned savings, the stress and uncertainty have pushed me into a state of significant distress. I've been trying to communicate with the dealer, but their responsiveness has been worst at best. I've provided ample evidence, including payment receipts, video recordings, audio evidence, and communication logs, but progress has been elusive. Now he says again that he can give a car, an i20 petrol model which is 5L worth at its best. But i am not sure he will give it fully clean also. I am turning to this platform for advice. What steps can I take to ensure a fair resolution? Are there any legal avenues I should explore to protect my rights as a consumer? Your insights and guidance would mean the world to me. I appreciate your time and consideration.