Wanna buy some cheap expressway toll coupons?

[Taro Toporific]

13 arrested over forgery of 4.8 million expressway coupons
The Asahi Shimbun--Thirteen people, including a crime gang leader, have been arrested on suspicion of forging an estimated 4.8 million road toll coupons worth 4 billion yen, police said Thursday.
According to information provided by the suspects, up to 3.8 million of the coupons may already have been exchanged for about 2.5 billion yen in cash, mainly at shops dealing in discount tickets, they said. Known as kinken shops, the shops buy various kinds of unused tickets at prices below face value for resale...more...

[Captain Japan]

From October 2002, they allegedly forged 4.8 million coupons, including 2.3 million for the Metropolitan, 300,000 for the Chuo, 500,000 for the Tokyo-Gaikan and 1.3 million for the Hanshin expressways.

This is the part I don't understand. The forged tickets have to be returned ot the toll offices in order to be used. It is not like forging money which can be dissipated anywhere. How could this scam have dragged on for so long - roughly two years? 4 billion yen? Once the first few forgeries started arriving at the offices and the books didn't match this should have been found out. There's got to be more to it than this.

[Mulboyne]

There's got to be more to it than this.

I think you may be right. However, the books at these companies don't balance in so many different ways that it might have been difficult to pick out this particular fraud. There was another scam which involved genuine toll tickets which was only picked up a few months ago.