SIM SWAP - Someone stole my number

Hi, Someone has made a SIM swap with my mothers phone number and the number was converted into a contract phone, I have been struggling with the issue for days now because the Vodacom helpline service is very poor not to mention going to two different Vodacom service providers they told me that it was not done on their branch there is nothing that they can do yet the person who did the SIM swap enjoys the courtesy of my call and private messages.... he even loaded whatsapp with my number *very disappointed and sad*