Samsung - Exploitation by Samsung Service Centre

we bought a brand new galaxy m** from amazon in December (it has ** month warranty) and it started having some charging problems in the last week of January so obviously its a manufacturing defect. My parents took it to our local service center (vegas mall dwarka sector-** new delhi ******, service centre code-*********) and being technologically less illiterate they were misguided and exploited by the staff there. They didn't register our complaint and didn't even take it to the technician. The receptionist told them to press it from back and told them to go back home without even touching the phone. The problem in reality never got fixed and we took it back to the service center this time too they didn't register our issue. We contacted the costumer care and they told us in order to get the specific parts the service centre must register your handset. so we forcibly got them to register our product.
Now out of nowhere they are saying that the warranty is void cause there is some minor scratch on the back panel which we werent even aware about. They themselves are admitting that yes we were exploited and there were no scratches before when we brought the handset to the service center but the employ who was working there and misguided us has left the center.
secondly even the new employs are so unwilling to cooperate they were so unprofessional and refused to listen to our problem.
One guy was specifically rude to my sister and was clearly being misogynist and was trying to suppress her voice. She actually got mentally affected by his completely unnecessary and inappropriate behavior and literally came back home crying. We would like to register a complaint against him separately. Also they refused to tell their names cause we told them we will complaint against it to their senior executives.
Also when i check the status of the repair through their website or talk to costumer service on phone they say its repaired and when we go to the center they say they haven't even opened the handset yet.
They say we will fix it for free if we get orders from our senior executives. We have contacted customer service on phone like ** times and every time they say we put the request on priority and you will get a callback from area service manager in **hrs but its been a whole month and we havent gotten a single callback from them.
My phones warranty will automatically get void next month cause it will be **months what will we do then.
The area service is Gurdeep singh. There are several complaints against him on this particular page as well. We tried contacting him on linkedin but we were ignored
My parents being less aware about technology were straight up exploited by the customer service staff and were taken advantage of. We want a brand new handset or this one repaired for free. Also an written apology and **,*** rupees compensation for the mental agony suffered by her.