The callers are likely blocking their caller ID and some of them are Robo-callers. COX can do little to change that, the suggestion to change your phone # is about all they can do. Likely that the calls are originating outside the US, so nothing that the government DNC list can do to help.
Does anyone have an idea why we have been getting calls to our land line for over a year that are identified as UNAVAILABLE? When answered, the line is dead! No one there. We can get 10 to 15 of these calls on a bad day and maybe none for several days. COX can not block these calls. Their only solution is to change our number. I have bought a small third party box that blocks UNAVAILABLE numbers, after one ring. We have to take the phone off-hook at night because even one ring will wake us up. Any idea what is behind these calls?

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