Flipkart - Different product receivedno replacement after multiple attempt

I have ordered Realme XT (*GB RAM, Pearl white) on *st october by exchanging my old lenovo k* note and i received the product on *th october. But they have sent me Realme XT (*GB RAM, Pearl blue). I have raised request for that * times but every time the seller rejected the request by replying that the reason is not correct. I talked to the customer care executive and they are just extending the timeline. They just kept on saying that the problem will be resolved within * days. From *th october i have been waiting to get a replacement but neither the customer executive nor the seller is helping me out. I requested the customer agent to make a request but they made a wrong request because of which once again the request got rejected. Moreover, Realme XT is at sale on Flipkart store but the seller is not initiating the replacement request neither he is accepting the refund request. The return window will close by **th October. After that, I will not be able to place any replacement or refund request. Please help me out. It's a humble request.