Samsung - Display issue not resolved

I bought Samsung M** *G on ** July , **** and within ** days , the phone's screen developed a flickering issue. I tried contacting the service centers and the Samsung helpline numbers who suggested me to update the software and run the phone through safe mode. I did as told and the problem still persisted. I took the phone to the authorised service centre and they also tried to eradicate the problem through software in which they failed. The problem still persisted and as of now , they have replaced the motherboard , the display and one more component and the problem is still there in the device. Although the frequency of the flickering has been reduced by some extent, but not completely resolved. I want to get my payment money refunded for the device and if not that , atleast the device must be replaced as soon as possible.