After my wrestling match with American Sexpress, I went to JCIC and checked my credit report. They are located near the Taipei train station. Their address and other details are here:
(Go to English version, public section, scroll down for link to credit report page)
It costs NT$100 for a credit report. I found the staff to be overall very friendly and helpful. If you have trouble filling out the form or understanding your report, ask for Mr. Sun Yi-shin (孫一心).
My only sore spot was a theft/fraud mark one day in June of last year (no charges were made) but they said I could have my credit card company remove that.
One thing that bothers me is that foreigners don’t have a credit score, and it lists the reason for that because you are not an ROC citizen or there’s been an ID number mistake.