A robo-call is an automated phone call that does not involve a human caller. The majority of these are uninvited solicitations (either for money or votes), and these are the ones I'm asking about. Robo-calls, being automated, are much less expensive for an organization to make than conventional calls, and are impossible for recipients to respond to. (Like spam but for your phone rather than your email inbox.)
Does halacha permit making unsolicited robo-calls? (I'm not talking about services you signed up for, like a weekly eiruv-status message, but calls that you did not invite.) Are such calls perhaps theft of the recipient's time and possibly voice-mail capacity or cell-phone minutes? (An unwanted in-person call could be too, but if a person calls the recipient can tell the caller not to call again, and in the US the caller has to comply. If there is no human on the line then this option is not available.)
Lately I have begun to receive unsolicited and unwanted robo-calls from Jewish organizations, which came as a surprise to me, hence this question.