I'm not sure that I specifically understand the premise of the question. The Customs Act does have a recourse process that people can go through if they have questions around the customs tariff that's been applied to their goods and a recourse process around licensing, etc. There are a number of recourse provisions that exist in the context of the Customs Act.
My first suggestion would be that they avail themselves of those particular recourse processes, depending on what violation they have apparently found themselves running afoul of.