HI zhiz,
Thanks. I've called town council but they said they are not in charge for that, they need to find out which dept that is able to take care of my case. They will call me back tomorrow (which i think it's very unlikely)
Called HDB, they referrred me to Commercial Properties. Talked to the officer. Same reply, they said they will check and get back to me "shortly", but it's passed the whole morning time, no call from them also.
Sigh.