If the quit rent bill is addressed to you then you have to pay. There's no 2 ways about it. Quit Rent is like what it says, a rent. Eventhough it says "freehold", the land isn't technically free because it still belongs to the state and you are renting from the Sultan/King.

If you are still in doubt, have your solicitor conduct a land search or you can conduct a land search yourself at the relevant land authority and the land search report should reveal that you are the registered owner.