What do you do if somebody you don't know called your phone?

Answer 1

You can always answer and find out who it is and tell them to stop.

Or set-up a way to just automatically block the number from ever coming depending on the type of service provider you have and what services you have. You may have to talk to your service provider about that. Good Luck.

Answer 2

Keep a big metal police whistle right by the phone. As soon as you are aware it's a "weird" call,

blow the thing for all you're worth right into the receiver. You won't have to do that more than once or twice.