Very irritated

My phone number was hacked and a sim swap done on my number. Then an airtime advance of R110 was done on the number. When I called to check why I wasnt able to access my number I was to about the sim swap. So how does someone do a sim swap, when I myself struggled answering the security questions. It clearly shows that whoever done this works for Vodacom. And now I am still expected to pay back the R110 advance. Why does no one want to tell me who called/or what number called to have the sim swap activated? Clearly they know what is going on and is just not willing to protect of assist their customers