My Samsung cell phone had a built-in flaw. It would reject a call if either of the ring volume control buttons were touched while the phone was ringing. There was no way to disable the call rejection feature. The exposed ring volume buttons do not require flipping the phone open to reach them, but they are also vulnerable to accidental touches. It is virtually impossible to withdraw the phone from a pocket or phone holster without touching the ultra-sensitive buttons. The genius who designed the feature probably had good intentions, but got poor results.
During the 18 months I had the phone, I became fairly adept at answering it without rejecting a call. But, no one is perfect. I had enough slip-ups, i.e. rejected calls, to make owning the phone something I wanted to end. As soon as I had the phone for the minimum contract time before I was eligible for an "upgrade", I traded it in for a model that hopefully would not have this design flaw. The AT&T agent assured me that the Pantech phone I had chosen would not reject a call when the ring volume controls were touched.
Guess what happened on the first call I received on my new phone. The call wasn't rejected; it was "silenced". I may have touched a damned outside button. I may be caught on a technicality, but the lesson is really a financial one. Make sure when you select a phone that it isn't the cheapest non-Samsung phone you can get.