Called, asked if "John" was there. I answered a terse "no". He said "no message, I'll call back later" and hung up. No John here. But I've gotten several calls asking for a generic name like John, Ann, or Mary on different phones. Usually when I say no, they go into a fundraising spiel saying they'll talk to me then. Phone makes a "bloop" sound when I pick up.

Received a call from this number but I didn't answer because I didn't recognize the number.  When I called back, the line is a constant busy.

Called, left no message.

Same as others. Leaves no message and when I call the number is always busy.

Calling on a Sunday unknown  number will never answer.  No message left.  Call blocking