One purpose in harassing you may be that the caller has an arrangement for "kickbacks" of sorts with a non-scrupulous phone company which your phone company is mandated to pay for the caller ID information provided.    The caller makes tens of thousands of calls, the bogus phone company collects fees for providing caller ID info for those calls, and then that phone company splits part of the caller ID proceeds back to the caller which pays them for making the tens of thousands of calls.   So, if that is the situation, they make money regardless of whether or not they talk to anybody.   If they do find somebody unsuspecting and naive enough to provide credit card information to them; then that is icing on their cake, so to speak.        

At any rate, it isn't a company wanting to do business (i.e., provide a product or service); but scammers wanting to rip-off anybody they can, at best.