Flipkart - Received faulty product and replacement refund did not happen

I placed an order on ** Oct of Boat Party Pal speaker with Mike of INR **** in sale. We received on **th Oct and when we realised it’s faulty(it was not working, no sound was there) we requested to replace the product. We were promised that the item will be picked up and a new replacement order has been taken. We just waited and waited but no one came to pick it up. We contacted Flipkart multiple times and they literally said that delivery guy will come by tonight or tomorrow etc. etc. We trusted them still no one came. They just kept on stalling us and we did not realise that they were just waiting for return window to be over. We raised complaint and they promised to replace again and said “you don’t need to be worried now, we will contact you now”!! So we were little relieved ! But ! It never happened. I contacted them again today on ** Jan and they said the case is closed!! I asked how can they close the case without giving any resolution. The agent had no answer he kept on saying that it’s not in his hands for half an hour !! He put me on hold multiple times and finally came back with answer that it was all my fault that I did not call them again when second time the order was cancelled!! I could not believe how here people.
It’s no longer about money. It’s about the time and energy these people consumed. The fake scams these people are running in the name of sale and return policy. It’s about the piece of mind I lost with these guys who are just robots and repeat the same things even if you talk to them for days! Customer service is zero and they lied to our faces. In the last call I observed the pattern of their call handling and how they try to put the blame on customer. I told them to write this on mail that the case is closed without being resolved and I will be convinced but that guy again started stalling me and eventually as expected hung up on me ! What is my mistake as a customer ?
Order ID - OD******************