Since the land already transferred to your name, it doesn't matter whether the house completed or not. You have to pay. That's why it is called cukai tanah, not cukai rumah. ada tanah, ada cukai.

Hahahahhaha, nope.... they are wrong.... I know this coz I'm working in Land Office.

Owh, another thing is, in National Land Code, anything on the land is considered as land too. You bought house that float eh?

Once your name is in the land title, you're responsible to pay the quit rent.... no matter whether the house have been built or not....