@mntmn The carriers (including the US Postal Service) charge additional "brokerage fees" for collecting the tariff. I don't think there is any way to appeal.
I recommend not selling anything into the USA, nor buying anything from the USA.
I'm speaking as a US citizen. The only way to fight this stupidity is to make US citizens so angry that we demand an end to these tariffs, and reinstatement of the de minimis exemption, and then vote Cheeto Benito out of office