Last year I bought a round the world ticket with IACE travel Japan. It was an open ticket with Singapore airlines (the best airline I have ever flown incidentally). A few days prior to departure my 2 year old was ill, and so I called the travel agent to ask if I could push back the departure date by a few days.
The agent wryly told me I would have to re-purchase my ENTIRE round the world fare!
So I called up Singapore airlines main office in Singapore directly to ask them if they could change my booking, as I had done a few times in the past as they are far more efficient than having to deal with the kafkaesque offices of any Japanese travel agent.
Singapore airlines told me that the regulations had changed, and I would need to have the travel agent change my booking, but confirmed to me that there was NO penalty at all, let alone the necessity to buy a new ticket, for changing the flight date as the ticket was open.
I noted the Singapore airline agent's name so I could quote her when calling IACE back. The agent at IACE appeared genuinely bewildered to discover that I was allowed to change my initial departure date (rather than just the following flights), so it would seem that the order to cheat customers by lying to them about the ticket conditions and making them purchase entirely new tickets (while pocketing the money from the first), came from well above: evidently such a scam works best if the subordinates dealing directly with the customers actually believe that what they are saying is true!
Eventually, after much time wasted calling back and forth between IACE and Singapore, IACE had no choice but to change my flight dates for free since this was the actual condition of the tickets I bought: having done my research I had caught them red-handed.
(But IACE still insisted on charging me where they could, for a ticket re-issuing fee).
Basically, IACE is exploiting the ignorance of the average Japanese traveler who has little knowledge of English and is unlikely to ever call anyone but their travel agent if any issues arise, and I can only wonder how many thousands of travelers they have ripped off in this way.