Sim swap *****

My prepaid sim card was sim swapped by somebody even though I had the number for more than 10 years. I received a mail to say R180 airtime was bought for my number with my bank account. This must mean there is a loophole in the FNB cellphone banking since they definitely did not have my password else they would have bought something else. I went to MTN in Cape Gate and they did the sim swap back no questions asked which is strange. After 5 hours the sim card showed a different number so I went back and they told me to wait till the next morning. All this while the ********* can use my number to try and get into my gmail etc. The next morning came and still the same issue. They told me to speak to Warren (second in charge). Went back to to Gape Gate for the 3rd time and he said it was done incorrectly so he did it again. He gave me his number and told me to phone him if the sim swap has not taken place after 5 hours. 5 Hours went by and I called him so he told me to whatsapp him the number so that he can check it again. 3 hours after that he has not read the whatsapp and does not answer the call. My bank card and online banking is now blocked because of this and I cannot reactivate it until I have my number back. It also seems unlikely that someone randomly chose my number. I suspect someone somewhere probably not Gape Gate MTN gave out my info and did the sim swap in order to try and ***** money.