tried twice today

My call blocker can hang up on callers based on their name or any portion of it.  As well as numbers, area codes, and has both a white and black list so it pretty much ignores everyone except the people and companies I really do business with.  Plus it logs all entries with date and time and allows searches for repeat offenders.

CID: *DATE*08172015*TIME*1018*LINE*-*NMBR*16266994577*MESG*NONE*NAME*SRVC CALL*
HUP: *DATE*08172015*TIME*1634*LINE*-*NMBR*16266994577*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*08182015*TIME*1701*LINE*-*NMBR*16266994577*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*08192015*TIME*1811*LINE*-*NMBR*16266994577*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*08202015*TIME*1156*LINE*-*NMBR*16266994577*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*08202015*TIME*1841*LINE*-*NMBR*16266994577*MESG*NONE*NAME*ALARM CO*

Other numbers they have called from:
ADD: *DATE*07022015*TIME*1933*LINE*-*NMBR*15624516742*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*07082015*TIME*1337*LINE*-*NMBR*14352556595*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*07152015*TIME*1237*LINE*-*NMBR*15105565347*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*07212015*TIME*1539*LINE*-*NMBR*14695023502*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*07282015*TIME*1350*LINE*-*NMBR*18177968958*MESG*NONE*NAME*ALARM CO*
HUP: *DATE*08122015*TIME*1354*LINE*-*NMBR*19093477197*MESG*NONE*NAME*ALARM CO*

Over the last 8 weeks we have received calls from this number.  We have a "Land line". Our caller ID says "West Covina, CA" each time. We have experimented with a number of responses, i.e. taking the phone off the hook and just leaving it lay on the desk top without saying anything (this should cost the caller extra money). We have also screamed (and I mean a wordless scream) into the phone. The calls keep coming.  For the most part we check the caller ID first and if is says West Covina, CA we don't answer it.  No message has ever been left. Sometimes the call cuts off after 2 rings (our caller ID picks up after 4 rings).