I went to the one in changi city point and they were rather professional - confirmed it was a HDD issue, but since it was PH on Monday, they will only look at it today it seems. No remarks about ding here and there on the MBA (yes it dropped from table due to the angle it was resting on, so there was some small ding on it). Asked about how long will it take, the fellow say at most 3 days.
Everything done within 30 mins, but then I guess I was there first thing in the morning when they opened - Not sure how it will be when they are busy; so far seems to be good.