unacceptable response from service manager level on faulty parts

When i purchase my Renault Sandero stepway in 2019 the clutch started to shutter, after numerous times i mentioned it to the service department they test the vehicle and say they cannot find anything wrong with it. When i took my vehicle in for the last service i mention this to them again and now they want to replace the clutch quoting me 22K to repair. When i told them they could have fixed this long time ago and claim it on the motor warranty the service manager say it was a long time ago and he can't do anything of what happened in the past. now they want me to pay for this. unacceptable to receive this response from the service manager.