Re: But where did the money go?
My understanding is that the money was never missing, the system has a very dodgy method of reporting transactions back to the central server. It worked something like this.
1. customer withdraws money from Post Office.
2. local system logs the transaction as being completed
3. local system attempts to send that information back to the server
4. if there was a connection failure during the reporting back of the transaction, local system gave up
5. At some point, the local system then deletes the local logs (possibly immediately after the aborted transaction upload).
Therefore, the discrepancy are valid transactions which the local software didn't push to the server properly, at the end of the day, the tills would appear to be down on cash compared to what the server was expecting by the sum of the transactions which didn't get reported back to the server.
Post Office / Fujitsu then started trying to reclaim the difference in money that their own software had created out of thin air.