Now, the song is on my phone's playlist since somebody converted it to MP3! :D It was posted on Sam's Facebook Fan Page. Sam has two "main" fan pages on facebook - the other one's inactive but it has the most likes. It is at this page that I found the download link:
http://www.facebook.com/pages/Sam-Concepcion/369827804235
Just head to the admin's wall posts and check on an April 17th post saying " with a link to 4shared which is a filehost.
By the way, here's the Youtube video I was talking about:
Video courtesy of ABS-CBN and "gRe3nArChErS" of Youtube