Samsung — My Samsung Galaxy A71 display has been tampered with at Samsung Service Center

I gave my Samsung phone model number -SM-A715FKWINS, dated 19/10/2019 at Samsung mobile authorized service center ROUSER MOBILE KAMTA COMPLEX NAWADA, Ara (BHOJPUR). It was said to me that the phone's display is damaged and it will cost about 8000 rupees, out of which I paid half the amount in 4000 rupees in advance. About 2 days later, a call comes from the service center and I am told that along with the display its motherboard has gone bad, whereas earlier when I checked the phone in my presence, I did not say anything like that. When I spoke about going to the consumer court, he corrected the phone after about 14 days on the previous due amount. Since I had already suspected that something was wrong with my phone, so I reopened my phone at another authorized Samsung service center, they said that the serial number of your old display has been tampered with and Serial number has been badly destroyed and the old display I got is not mine. And the display has been thoroughly cleaned and the tape of bettery has been completely removed. And the invoice date has not been included in the bill that has been given.