Open Question: How much do you think I should claim for damage to item in my home?

I had cleaners in my home and they managed to scratch my stainless steel fridge freezer. The scratch is roughly about 1 1/2 inches. I know it's not major damage but it annoyed me as it was under 6 months old and I had been very careful myself to keep it in good condition and also because these people were supposed to be improving the look of my home, not making it look worse. I have spoken to the man in charge a couple of times but we haven't worked anything out yet. I would have been happy to have it repaired but he said he's spoken to a few people and it's very unlikely it could be repaired. He then said that their insurance wouldn't pay for a new fridge freezer but would pay for loss of appearance and then asked me how much I would be looking for. It cost £500 (after some discounts I got on it) and is under 6 months old. Considering it's not a huge scratch, but also considering that it was in mint condition before they scratched it, what do you think would be a fair figure to ask them for? He had previously mentioned about either getting the fridge door replaced or giving me the cash equivalent, and I said I'd be happy with that. I don't think they actually do replacement doors, therefore I have no idea how much this would be.