yes, customs can be a nightmare, and not only the fee. I had a friend who ordered a bathroom scale from Amazon and customs told him it was classified as a “medical device” and he needed an import license for it.
I’ve never done it myself but before the pandemic a friend came to visit on visa exempt. He went to get an extension and he told me they only gave him 15 more days. So, I don’t know.
technically speaking it does not remain their money. It becomes the bank’s money. The bank then owes the amount to them. In a financial crisis, they might not get the money back. If you doubt me, study what happened in Cyprus.