I ordered the rack from them and received it via air freight less than a week later.
Their charge-first, check-inventory policy sounds like it needs changing. From what I hear from Americans that have worked in Japan, the culture tends to be very strict about 'rules' and following them to the letter (maybe some of you here that are currently in Japan can comment or correct me). If that's true then I'm not surprised if a request to adjust the transaction would be met with a 'no rule bending' attitude.
Sounds like a crapshoot.. had the exchange rate been favorable to the U.S. that day, you would have gotten back MORE than you paid..