Thanks in advance for any and all help!!!

I have Excel 2007. I have a file of that contains 3 sheets of similar
information - account number, balance, name, due date, high credit, etc.
This is a non-logical segmentation of my company's entire card base (I work
for a small card processor). Unfortunately, in converting the original
information prior to segmenting accounts, it was not discovered that Excel
only converted 15 of the 16 digits of the account number, changing the last
number to zero. I was able to re-import my original information - importing
my account number as text instead of numbers, so that now I have a file with
the correct account numbers, but they're not segmented in to my non-logical
groups. I tried doing "Remove Duplicates" - by comparing the names, but that
didn't do anything. I can't do "remove Duplicates" by balances, since there
are a great many cards that have a zero balance, and I can't match "John
Doe's zero balance card" to "Jane Smith's zero balance card".

Short of comparing all 9500 lines of the file and manually segmenting the
cards again, do you awesome gurus have any suggestions?

My incorrect, segmented file has incorrect account numbers, like
1234-5678-1234-5670, when the correct non-segmented file has the correct
number like 1234-5678-1234-5679