Customs levied a tariff on my package despite an existing free trade agreement?

[namazu]

Hi all,

I received a customs tax bill for some porcelain tableware sent from Singapore to Malaysia, even though there is a free trade agreement between both countries (ASEAN Trade in Goods Agreement (ATIGA)). 

The total amount of tax levied is 30% (tariff) and 10% (sales tax), which adds up to 40%, not including the miscellaneous administrative charges.

I am fine with paying the sales tax, but I believe the additional tariff has been mistakenly applied. It's quite a large amount, and honestly feels unfair given the free trade agreement.

Is there anything I can do about this?