Perhaps if hit with the additional segments issue in the future, just include the ones you want on the OWE ticket and then book the extras separately via the web.

Seems the major problem (as noted by others) was the initial time to get back to you, and by then your options for resolution were severely restricted.

I have had many, many OWE tickets issued by TA's in Australia through QF and never had any problems. They normally validate the requested itinerary and quote the ticket price within a few hours. So something went severely wrong in your case and I also suggest you contact QF and bring it to their attention. They are normally very at resolving issues like this.