Originally Posted by alect
In fact a date change does not require a ticket re-issue at all. Just change the date/flight on the reservation (you can do this with your FF airline or LA/QF) and just turn up at the airport with your ticket as is. Reissues are only required where the routing changes.
Airlines believe that a reservation made by a TA belongs to the TA, not the passenger, until after the first segment has been flown. That's the reason for the refusal. And the TA has to make a living and be paid for his time somehow, so a charge probably isn't out of line. Presumably he's a good TA which is why you booked through them in the first place, and you're getting your money's worth.
If you want the airline to change the res for you at no cost, as with all things related to the industry, if you call enough times you'll probably find an agent who'll do it.