I did get a phone call months ago when all the changes were first announced.
There was a lot of back and forth both by me and the person who called me. We both pretty much ended up sticking to our guns - he said the changes are here to stay, I vowed I would not fly an airline that valued only some of my business.
I'm almost out of vouchers and come January or sooner, I will go the way of Mr. Blutarski - zero...point...zero paid flights on Delta.
Thankfully, AA and US appreciate all of my business. And for the moment, both cooperate quite nicely with QF.