Poor protection of my personal details

Most terrible experience I've had in a long time. Had amount of R12000 deducted from my account by a contract that have been created on my name in Hi-Fi Corporation in Johannesburg. How does Mtn protect my personal details. Had to run up and down from Mtn stores and then made phone calls and then create a case at the police station which i couldn't do as it happened in Johannesburgh and I live in Cape Town. Have to wait for the police to come to my house to log the case and then supply Mtn with a case number.