In defense of the OP, and this is a weak defense I'll admit upfront... and for all the newbies here, listen good.
If you've had the type of problems you've mentioned in your OP, you have to complain to US and also file a complaint with the DOT. That's the only way to make US accountable short of what others have suggested in taking your business elsewhere.
Tempe thinks things are fine with the number of complaints going down... but I think we all know better. Statistically, they are still the lowest in the DOT complaint ratio that the DOT measures this quality measure.
I hear bad experience stories from FFOCUS members everyday both on the FFOCUS forums (yes, we have a forum area on the same idea as these on FT, except more detailed) and by individual members who have emailed me.
I wish something like a class action suit would make Tempe wake up, but all Tempe is concerned about is making money. As long as the yields are high and $$$ is being made, all will be fine according to their standards, so I hope you can deduce what has to happen for them to really listen.