For over a year now I've been getting calls with silence on the other end.  In the beginning it was a few calls a week.  At first the number was "unknown."  As the calls became more frequent, caller ID started showing "3-994."  Now I get about 90-120 calls a week from 212-381-9060.  They almost always come in sets of 8, one after another(every 30 seconds or so).  Once a month I'll get a set of 4 or something.  Sometimes I'll get 24 calls in one day and nothing for two or I'll get 8 or more a day for a couple of weeks straight.  Of course each call leaves me a voicemail so I fill right back up after I empty it.  Same silence as the calls in the beginning.  I'd change my number but I don't want to renew my contract with t-mobile.  Also it will be a pain in the [***] to tell everyone my new number.

Obviously T-mobile won't/can't do anything about it.

212 is Manhattan somewhere.  I assume my number is in some bugged tele-marketing caller that someone forgot about.  Especially since I now see the number where before it was blocked.