Caller: A charity call centre

I returned missed call. A message stating it was an (unnamed) charity calling me. An email address is given to opt out.

spam - called back and it went straight to music/hold. I don't know of anyone with this area code.

Caller: A call centre for charities

Called back and received an auto response. Stated that the call did come from them and it was from a charity I either already support or one that's contacting me for first time.