Sim Swap without right documents

<p>i have a GDE sim card i got from my brother when they got contracts via sci-bono. i've been using this number for two years. on the 24/11/2016 i got an sms from vodacom saying they have received request for a new or replacement card. i called in to say i didnt request for sim swap, but the sim swap still happened. today 05/12/2016 i got the very same sms. when i went to vodacom randburg for sim swap on the 24/11/2016 when this happened i was told they need a letter, but i dont understand how they did it earlier that day without that letter. my problem is that this number is linked to my bank account. and if this can happen within 2 weeks how are we safe at vodacom? </p>