The cruise control switches on my 2012 SE are indeed a horrible design. My CC never worked 100% since day one. Some days only the on/off and '+' buttons worked. On other days nothing worked. After almost exactly a year and 24000 miles it seemed to have finally failed totally.
I was actually very happy about that, because I knew that the dealer would almost certainly say 'works for us'.
So I took it in to a dealer. Latter that day I got a call. 'The computer says the CC works, and it worked on our test drive.' But they did do the wiper and transmission software recalls.
So I pick it up, not totally surprised, since I suspected the switch assembly all along. They said they had test drove it, but the 'miles to empty' readout hasn't changed. I think they did some kind of computer reset on the CC, but didn't really drive it.
I pull out of the dealership. It won't work, but it's failing in a different way. Before it would typically turn off with any button press on its bad days.
Now it turns on, I see the 'Set speed' display. But neither the + or - switches do any thing.
Back to the dealer, leaving the car running I kidnap the service writer and demonstrate the problem. Latter the service writer calls to say it may be a day or two to fix.
Two days latter they call and said they have replaced the switch unit and now it works.
I pick it up, pull out of the dealership, and indeed it works! After a stop I try to engage it and again it will turn on, but the + and - buttons don't do anything!
I start to freak out, so far I've been very patient. On a hunch, I flick the resume/cancel paddle several times and now CC works!
So clearly my second switch assembly has some kind of intermittent problem, just like the first one.
This is a serious design flaw in another wise very nice car.