Who called from 3050000000

There must be method to this madness. Can't any phone company find out who this is? STOP IT already!!
Nobody is listening to the calls anyway.

Blocked but still rings once ... over and over and over ... every 20 mins or so

They call every day and when I answer there is no one there then they hang up. What can I do to stop this?

Called 4 times in less than 3 hours! I will not answer!  Have been calling twice a day for several days previously!  Sick of it!

Have called my cell phone (my only phone) for days, never leaving a message.  After the 8th call today I finally called back.  Got the message "your call can't be completed as dial......"  .  Sick & tired of this.  If anyone knows how to stop this please post the secret!