Don Wiegel, CUGG
The culprit is probably PREDICTIVE DIALING
Predictive dialers are complicated, automatic telephone dialers that are used by telephone sales companies to contact as many prospective customers as humanly possible. By eliminating the time it would take a human to manually dial a phone number. The problem is when the number of calls placed by the computer is too high for the number of people manning the phones; the result is ABANDONED CALLS on their end. The next problem (for you) is that the computer will probably recycle your number, resulting in another call to you. The telemarketing industry really does not care if they drop 50 or 60 percent of the calls, because who are you going to report? You don't have any names or even caller ID information (they block this). If you try to investigate, it won't lead you anywhere. Did you know that the telemarketing field is very lucrative—700 billion in revenues last year alone.
By the way, most telephone companies sell call-blocking services.