Cell C Sim *****

Hi my name is T.M ********** 160.....been a loyal Cell C customer for over 18years now. Started with the same number on contract for about 4-5 years then ported it over to prepaid. Now Im told my number is owned by Jeraline Carlos da Costa yet ive never left this number ever.

After buying a new phone I couldnt sim swap the number since its now not mine alone plus cell C says its my duty to find the *********. I dont believe this is right. how did they double register the number when it was still in use? How do i rectify this?