The mystery solved

The mystery object on the left is a transverse section of the Department of Housing's response to an account inquiry by DH, listing 6 months of rental transactions. Extraordinarily for a department that DH knows spent a fortune on a state of the art computer data warehousing system not so long ago, it appears that after decades of advances in computer technology, the Department doesn't appear to be capable of creating a simple report.
The document you see on the right is a full frontal view of the "mystery object". It's a series of screen dumps painstaking glued together by Housing Department staff. Despite their efforts, it is pretty much unintelligible, even by Department staff.

DH made the request because she has a tribunal order to pay back rent arrears at $150 a fortnight. She was just about to make another payment when it occurred to her that the debt might be paid off already. Inquiries with various housing department help lines, gave her 3 different responses, including

1. You are 4 weeks in arrears
2. That's funny. According to this you should owe us $2000 (DH nearly had a heart attack at this point.
3. You are $50 ahead

Finally, it turned out that DH was right. She was $50 ahead. Hurrah!

However: She wonders what would have happened if she was, say, learning disabled, poorly educated, unable to speak up for herself, etc etc. How long might she have gone on paying back arrears at a rate causing her serious hardship before anyone at D'oH noticed?

It's quite extraordinary that the Department's procedures and formulae for working out rent due are so arcane that their own staff must spend an hour working out something that ought to be accomplished at the push of a button!