Allow me to clarify the below points,
1. All expenses according to invoice number IV0001289 is our payment in advanced to port and shipping line with official receipts. It is clear from the quotation which comprises of our service charge only, not included in our part. When quoted, we have never been aware of the shipping terms the shipment will be (in some case, all destination fees are paid at origin) and also which shipping line you/shipper will nominated – how come we can quote including the unknown charges? I assume this is a normal practice being used elsewhere.
2. From the attached email message, it is clearly stated that 6,000 THB is additional charge for customs declaration and clearance. So, the extra amount is 6,000 THB not 2,000 THB.