Originally Posted by
TVTravels
I was shocked at her statement as I was just trying to educate myself on how the rules work.
Your best education is searches on ITA like:
yyz:: pek /f ac.yto+bkk
bkk:: /f ac.bkk+yto
You'll find that AC's through-fares with stopovers are possible, but only in unrestricted (expensive!) fare classes. Save the cash & book a ticket combining three fares.