Multiple calls over several days... very annoying. So glad they don't call in the middle of the night! called back and "this line is not in service message" is on.
We have received three calls from this number this morning. First two, no one there, third time I waited about 15 seconds and someone said "Hello". I asked who this was and they hung up. Reporting them to the no call registry.
If your number is listed in the National Do Not Call Registry, you can file a complaint here:
https://complaints.donotcall.gov/complaint/complaintcheck.aspx