Called right back and line went dead.

Called number back line just goes dead no ring or nothing

SOBs call incessantly.

Couldn't hear caller, sounded mechanical, then line went dead

These people are persistent I will give them that.  I am still not going to talk to them.  I never answer calls from "OUT-OF-AREA" or any other caller id that will not identify themselves.  They started calling this month and have not given up yet.  Good thing my call blocker can block based on their name as well as their number.
HUP: *DATE*03032017*TIME*1407*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03032017*TIME*1439*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03082017*TIME*1408*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03102017*TIME*1403*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03132017*TIME*1013*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03152017*TIME*1044*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*
HUP: *DATE*03162017*TIME*1155*LINE*-*NMBR*12817849005*MESG*NONE*NAME*OUT-OF-AREA*