$100 package valued at $1600+?

My MIL recently went on vacation in Japan and brought back a few souvenirs for my wife. This includes:

• a labubu blind box (1500 yen)
• a faux leather bag (2000 yen)
• a couple small sanrio plushies (~3000 yen)
• a watch (2300 yen)
• a chopsticks holder and a few miscellaneous trinkets

In total, it’s just about $100 in souvenirs. She arrived back from Japan to the US, and mailed the souvenirs to our house in Canada. She told UPS the package was worth under $200 and sent it off.

Colour me surprised when the package arrives in Canada a month later with a $340 Collect on Delivery fee. Upon closer inspection, customs valued the items at a total of over $1600, with the largest chunk coming from “Disney Plush Toys” at just over $1330 CAD.

The amount it cost to purchase the plushies was not even $50. Furthermore, none of them are Disney IP, so I have absolutely no idea where they got that part from. It would have been significantly cheaper to just have them toss the package and reorder every single item directly from Japan, but my MIL already paid it for us when I told her.

I’m struggling to understand how this happened. Did they just look up what a labubu costs and go with the most expensive collectors item they saw on eBay? We’re not exactly labubu enthusiasts or anything, I’ve never bought one before or even thought about it, it’s just something small my MIL thought my wife would like while on vacation. And where did “Disney Plush Toys” come from?

The only other times I’ve gotten such a high customs fee was when buying $2800 of recording equipment from Germany, which I paid happily, and when my MIL shipped some of my wife’s childhood clothes (>10 yrs old, heavily used) and they priced it as if each item was bought brand new off the shelf at full 2025 retail value.

What recourse do I even have here given that the fee was already paid? I recognize it’s not really the fault of UPS, it’s the glue for brains customs agent, but I don’t even know where I’d begin to try getting my MIL’s money back. It also doesn’t help that I watched the UPS driver football kick the package onto our porch, which is like— okay, it’s plushies, but not exactly how you should be treating a package you think is somehow worth $1600. If it was a laptop or something I’d probably be mad about that.