Samsung — Severe Display tint issue on S20FE 5g

Hi,
I saw a severe display tint on grey color throughout the device in low lighting conditions, I asked customer care for replace refund within 14 days of purchase and they agreed to it, they said to submit device in service center. The service center are denying this as an issue and are saying that this is not an issue but a theme I asked them if it is a theme, to download any grey image from net in another device and transfer to the defective unit and check if the issue persists but they said they wont check anything because they only check with whatever sw samsung has provided them with. The customer care person who was handling this case said he will ask them to send images and I collected my phone after that from service center and the week after that I got the reply from customer care that no issue was found so closing the case.