Sony - Defective Sony headphones

I purchased a pair of Sony Bluetooth headphones (model WI-SP***N) in **** which cost Rs. ****. Within the * year warranty period, I faced a number of issues for which I made multiple trips to the service center which cost time, money and effort on my part. Sony addressed the product issue by replacing the headphones. The product replacement however, did not solve some of the issues. Later on, past the warranty period in ****, the device would not charge. Upon bringing this to the attention of the customer service team and requesting them to escalate this issue, by requesting to speak to their superior, they unprofessionally denied my request. The resolution that Sony adopted was a “**% discount” on an upgraded model which they claimed cost ~Rs. **,***. On Amazon and Flipkart, the upgraded model costs ~Rs.****. At the end of the day they are making me pay ~Rs.**,*** for a faulty product. I used the product the way it was meant to be used i.e while exercising and making phone calls. Further, their attitude and conduct is offensive and despicable. I want a complete refund and they are not acknowledging my request.