Calls but never leaves a message.

Received two calls from this number on my cell - which is a number I registered on the Do Not Call list (clearly, that doesn't seem to make a difference). It's a debt collection scam.

Same issue as ShawnM.  Different numbers, always starting as 386-804 (one ended 4298, and another ended 2589).  Same taped message: "serious call about my credit card balance, nothing wrong with my card, but it's urgent that I press 1 and speak to a representative about my credit card balance; first call on  01-22-16 @ 1520, second on 02-18-2016 @ 1411.  Both times pressed to speak to a rep, got one, asked to be put on DNC list and they immediately hung up.  Blocking a call isn't an answer, since these jack-wipes appear to change phone numbers every few weeks--specifically to be able to make new automated calls to phones that have blocked previous numbers.