Forgive me for what may be a noob question, but I am traveling on a UA Award ticket BOS-SFO-NRT-SIN then BKK-HKG(stopover)-YYZ-BOS. I have the flights all booked out, but we looked at our schedule and decided that we wanted another 2 days in BKK before flying to HKG. We are currently booked on TG606 on Dec 17th in Y. I checked Dec 19th on the ANA tool and it shows total availability for the same flight the 19th for 2 adults. However calling up united I got told there was no availability at all on those days. I don't know if this matters, because I am pretty sure I am talking to India now and did so when I booked the tickets, but I am calling Mileage Plus Australia, because I am in Australia right now, but I booked the tickets through the USA. Is there anything else I can do other than keep calling back?