who is this? they keep calling me and hanging up and have been for months

This is the first time I have recieved a call from this particular number.  When I answer there is just silence on the other end for about one minute, and then the line goes dead.  Does anybody know where this is coming from, or having the same problem that could shed some light on the subject?  Many thanks ahead of time....

The same thing is happening to us it started this week they are calling 2 and 3 times a day and hanging up, or if it goes to the answering machine, no message is left.  Sure would like to know who it is......thanks.

I have them blocked in my cell phone but it still drives me crazy when they call. I am going to find out who and where it is coming from and I will post it.