get calls daily from this number-they never speak or leave a message--has to be spam

Caller is Jo, a woman who claims to be from a senior agency or group.  If I block the number I get cals from another numberbut it is still Jo.  Sometimes it seems like there is actually a person, but the computerized system is just picking out words and responding accordingly.  Multiple calls throughout the day.  Sometimes it just disconnects.  Never a real person...never a message!