Who called from 7182246680

This person or persons call my line several times a day. Since I do not recognize the number, I do not answer the call but it is very annoying. How do I block these numbers?

This number calls twice a day, morning and afternoon.  I never answer because I do not recognize the number.  They never leave a message.

This number calls twice a day. Do not know who it is. So I don't answer. anointing as hell.

This number keeps calling.  They state their name is frontier and can save you money on your energy bills.
Return call to their number states it is not in service.  Do not give them any information.

Getting the same issue with this number. Very annoying