I bought a computer online from Singapore. Under the ASEAN Free Trade Agreement, it is exempt from import duty. The Singaporean website I bought it from quoted the price (THB105,930) as including all relevant taxes. The price in Thailand is quoted by the Thai distributor as being THB99,000 plus VAT, which is THB105,930. Thai Customs are trying to charge me VAT on this item. Are they correct, or not?