Samsung india electronics pvt ltd - Hang Issue

I have purchased Samsung S**+ Mobile Flipkart Big Billion Days Sale on Oct **th in a scheme which says to pay **k and then the remaining **k in the next year to either keep this phone or can exchange this phone for another one. Its only been *-* months that I have purchased this phone and have constant phone hang, overheating and battery issues, hence reported the issue to the support team. They have informed me that they will get this checked by the support team and then give an update on the replacement or refund of the device. But after getting it from the service center, they have informed me that the issue is fixed and I will no longer face issues, but to my surprise the phone hanged again the very next day while answering normal calls. Hence I have sent an email along with Screenshots to Ms.Sushma and requested cancellation of the product as I was fed up with the service they provided so far and also that the phone hanged even after giving it to their own service center. But to my surprise, they are not even bothered that my phone hang issue is not fixed but directly told me that it cannot be replaced or given cancellation and neither bothered to solve the issue i was facing. I have faced such pathetic irresponsible careless service from Samsung. Even during the process of giving me an update about cancellation and also to get it to sevice center they have taken so long and did not follow up with me on the promised time they have told me to call me. I always had to follow them on email and only then they would respond. Im totally dissatisfied with the service and would never use SAMSUNG products ever in my life nor would recommend anyone as not only they sent a faulty device but all their employees do not care about customer's issues nor properly followup with them nor even bother to fix the issue. I would like to proceed legally in this regards to the same if they do not refund my money as the phone is under warranty and had been barely *-* months and faced such pathetic experience not only with the phone but also with Customer Support and also including Ms. Sushma. Sr Executive from Customer Support team who was so irresponsible nor to follow up or to solve the technical issue that i was facing with the phone and failing to speak to the customer properly.