If you choose flexible and/or non-refundable economy and then select a Q fare from the list then the stupid software reverts to the lowest fare for the selected dates when it asks for payment. I suppose it's programmed like that to give you the lowest fare, which is what 95% of the customers actually want.
I even found if you select flexible, and then select refundable it still reverts back to the cheapest V fare. That's *really* annoying. It only works if you select specific dates.
..... you simply have to do this type of fare on the phone.