Contact TakaraTOMY and tell them. They actually take complaint calls seriously.

When I called to complain about a missing part on my MP Convoy they FedEx'd me replacement parts (with free gifts as an apology!) which arrived in just a few days from lodging the complaint! When I called them about Encore Ironhide/Ratchet not being on their online survey database they corrected it within 24 hours!

Customer Support page
Online support form

The Customer Support page lists several call centre numbers that you can phone - just remember to add +81 for dialing Japan from overseas.
e.g.: 0011-81-3-5650-1031