Dear Sir/Madam:
Thank(s) you for your quick response (so quickly). (Till now,) I still have not received the (file number) letter that you resent to me.
I am sure the mailing address provided on my file is correct(available), however, (My)the mail might be delayed or lost(missed) by(in) China Post(al Service). Since the really important information in the letter is the file number, w(W)ould you be able to send me (please kindly send) the file number via email or an alternate method(by another way)? (Sorry for the inconvenience) I really appreciate your help.
(Thanks&)Best Regards
Woaitaotao