Sim Swap *****

On the 2/12/2015 at 7AM woke up to a message that said I had requested a sim swap. Contacted Vodacom to ask whats happening they said someone had requested a sim swap on my number, they advice me that I should go to their Shop and do a sim swap to claim my number again of which I did. They gave me a reference number S39029WWIII promising to contact me ASAP of which they never did. My number was unlock the following day on the 08/12/2015 but still I could not make calls, contacted them again to ask what is going on could not get an answer for that. I have been waiting from 02/12/2015 till today 08/12/2015 with a phone that I cannot make or receive calls from. I just want vodacom to tell me how is it possible that someone can do a sim swap on a contract phone of my number over the phone CALL CENTRE.....?