Calls being dropped/disconnected/lost without cause.

[skaiser]

I have called at least 5 times regarding this issue.  I have received a warranty refurbished replacement, on the next call a new SD card, and just keep getting the "run-around" as to why I keep having calls lost/dropped!  This ALWAYS happens a few seconds into the call, shortly after the greeting.  I have watched to ensure that the proximity sensor has gone dormant, and I am not touching the phone to my face.  I am not pressing any buttons on the outside of the phone (which has an otterbox defender case and screen protector on it.)  It doesn't matter if the call is incoming or outgoing.  I have done the soft reset (volume down and power button held for minimum 15 seconds) as well as powering off and leaving for several minutes and rebooting.  I'm stationary 98% of the time this occurs.  And while service in city limits is QUESTIONABLE at best, most of the dropped calls seem to happen within 1-2 miles of the nearest tower.  This tower, however, is not a Verizon tower.  I have reported ALL of this information NUMEROUS times and still have no resolution.  I would just merely like to have a phone that does that I'm paying for it to do without constant frustration and troubleshooting.  PLEASE HELP!