Calls me on cell, comes up as missed call, busy signal when you call, nobody there when you answer and disconnects immediately

I answered the second time they called tonight, it's a solicitor. Told them to remove my number and not call back.

the same thing is happening to me

Same is happening to me.  Calling - no message.  I don't answer, but they keep calling me back.

This number has called me twice today within an hour. When I answer, the call disconnects. When I call back, all I get is a busy signal. Very annoying.