Vodacom, where are these numbers coming from?

Past month I have been getting these spam marketing calls, told the guy I'm on the DMA no not contact list, but he keeps claiming he's not selling me anything, have put the phone down on him twice, but I see today I got yet another missed call from a number that follows a similar pattern to the previous ones - +81 3-0000-01 and +81 3-4441-11. Does Vodacom know where these numbers are coming from and that spammers are using its network to harass Vodacom clients? Whoever he is, he's getting info from somewhere, because first time he asked for me by name, the second time he mentioned the name of my personal business, which is not is not linked to this number.