I have finally gotten Chinese email to display on my BB. The long story short, T-Mobile and RIM couldn't solve my problem (see my above posts).

Here's how I did it:
I borrowed my colleague's BB that shows black squares in place of Chinese, to switch handsets but couldn't send service books to neither handsets. Then I deleted my service books on my handset with my colleague's SIM card and thinking this may be the problem of not able to send service books. For some time longer, it still didn't work. In feared of screwing up someone else BB, sort of gave up and reversed the SIM cards. After a while I was happy that both BB started to work. Then I did a test just for the hack and wow there they were. I can't believe I fixed it!

Though I still don't know exactly what fixed it. I doubt that deleting the service books would because I did try without backup and restore. I think it's the setting on the BIS that was stuck on since I first had my BB thats probably on BIS 1.0.

Hope my experience would help someone.