Unauthorised sim swop to contract cell phone

On the 17th of March 2015 I received a \sms"from Vodacom informing me that a sim swop was requested and that I should contact there call centre if I suspect *****. On the 18th I phoned them to inform that I did not request for a sim swop and I also immediately visited there call centre .<br> I have a contract phone and only the rightful owner can personally apply for a swop when he must have proof of identification"