********** contract taken out on my number

Sitting at work today and i received an email to state that i have taken out a new contract. I was shocked. Im a long standing customer and do not expect to be treated like this. Someone took out a contract on one of my existing numbers and then sent me a debi check mandate for R18508 per month to approve. I called 135 and the lady said i should call back in the morning to cancel this new contract. Then i called your ***** line and was told to send an affidavit and copy of my id. In the mean time, im sitting with a brand new contract that i did not take out. Someone internally probably tried to make a quick sale and used my details. I need this contract stopped. I trusted mtn with my personal data. This is shocking. I will be going to saps and my attorneys and the ombudsman.