Someone opened a contract online using my personal details

Someone opened a contract online using my personal details. I didn't open an account or sign any contract with vodacom. I am currently using my own phone which I bought cash. My big question is how did they do verification. It means their system is very bad anyone can just get a phone from them without verification. This situation is now affecting my credit score. How on earth could I take a contract of R2000. I am not mad. That installment is for a car. I need them to do investigation to find out who they gave a phone to. Where , when did they deliver that phone. It means Vodacom does not do their verification. They must remove my name from their system and also update credit bureau about the outcome