If this is the manufacturers warranty (normally 12 months from new) any fault that has been complained about within that warranty period and is still apparent after that time should be fixed under the warranty. The dealers can be very evasive about this and will usually make excuses as to why they cant do it under warranty. Try talking to manufacturers customer care lines and elevate until you get a satisfactory answer (the manufacturers customer care lines will refuse at first but keep elevating to their manager etc.)