Samsung India Electronics India Private Ltd - not providing replacement for defective handset with two times motherboard complaint

sir,
i have bought a samsung s*plus mobile handset on **/**/****. I faced some range issues and battery draining problem from the very beginning of purchasing the phone. I contacted samsung’s service center at kollam, kerala (service center ********* – I cure solution) regarding the issue and they said it’s because of the old sim card that I am using. so change the sim cards and there will not be any problem after that and they will replace the device if the problem persist. later I changed the sim cards but still I came across the same issues. since I was out of station I couldn’t reach the service center after that. two months before I went there with photographs showing the proof of range issue and that time they diagnosed as motherboard complaint and I asked for a replacement as they promised before. but they refused the replacement and they can only provide repair service since only four months left for warranty to expire. later they changed the motherboard under warranty after that many other issues like heating problem, gps problem, sim card tray can’t be fully inserted and some scratches on screen and abrasion on side body. Then I contacted their customer care to complain against the repair issues and they suggested me to contact their service center upon a promise that they will rectify all the issues. Again I visited the service center on **/**/**** with the issue and they diagnosed it as a board complaint, still they are not willing to provide a replacement for a defective handset, and it is not acceptable to use a repeatedly board complaint phone although I invested a lot of money and time for this. So kindly please take necessary actions against the anti-customer rights policies of Samsung India and their service centers and provide a replacement for the defective device. The details of mobile phone and service request bill details are listed below.
imei : ***************.
serial no. : rz*j**xbnpw
model name: sm-G***fzkgins
service request bill no. (old): **********
service request bill no. (new): **********