Why was I charged additional taxes and fees at the post office (not in U.S.)?

We offer Free Shipping Anywhere for our print textbooks, and other items like t-shirts and bibs. This includes all the shipping handling and charges that the USPS charges us for international mail.

However, unfortunately, we have no control over what individual countries do at customs for additional charges and fees. Sometimes they add additional fees, sometimes they don't. And even the amount varies, not just from country to country, but even within country.

We're sorry about this, yet it's outside our control.