Well, after over a year, I've finally found a video of an advertisement that was aired on a Singaporean TV channel in Nov/Dec 2008.
My previous searches on Google have yielded no results of what this song's title is, although I have found numerous other requests for the title of this song as well. None of them had an answer...
So, could anyone here please identify the following song? Your help is very much appreciated.
YouTube - Central commercial - Letters