I was in the process of doing a trade in with a iPhone 14 pro

I was in the process of doing a trade in with a iPhone 14 pro. I did the online quote and was quoted a price i was okay with. I then booked a store visit for them to assess my phone. The staff picked up a small scratch on the back of my phone and has stated that they would pay me a quarter of the price I was quoted. That is insane and daylight *******. The staff was very rude.