No Reliability

I have been with Cell C since day one, this has been the best network for me,until my number ported to Mtn without me initiating the port, so this happened at 6 o clock in the evening, i receive a message " your port has been initiated" , I call cell c the lady tells me the port department is closed i should call back the next morning at 8 o clock, a few moments later i receive yet another message saying that my port has been successful, and i would have to rica my sim card in order for it to be active again, HOW IS IT POSSIBLE THAT SOMEONE IS ABLE TO GET ALL YOUR INFORMATION JUST LIKE THAT. these people had access to my bank account and all other personal details that was on my sim card. i feel like this is in breach of some form of contract between myself and my service provider!!!!!!!!