I got the same story today. Maybe we talked to the same guy. I wasn't even trying to refund, just change, but there was an error. He said that since the change was "so drastic" and "not even the same partner", that it probably wouldn't let him make the change and he'd have to cancel and start over with a new fee. He sounded very shocked when the system let him issue the ticket without another fee. I had some more flights I needed help with but decided not to chance it, HUCA.