sim swap

On the 8th December i phoned vodacom to do a sim swap which was done and i checked again on the 10th to make sure that the number was correct. the sim swap was working fine..however, today i get an email from one of my friends informing me that there were looking for me and coulnt get hold of me as my phone was constantly on voice mail. i assured them that the phone was working fine but to my supprise the number i was supposed to be active on wasn't working, phoned the call center was informed that the sim swap wasn't done and i need to go buy another sim card and rica it then phone again to be asked security questions. My question is why should i do that as i did it before and how sure am i that this will be done correctly. Can someone please fix this mess cause i might be missing on important calls as i have used this number to apply for jobs..not willing to buy another sim card. i know its cheap but y should i cause i did already, what must i do with the one that i have?