Bad credit record because of unknown Cell C account

I have a problem with my credit score because apparently I have a Cell C account that I know nothing about. I was applying for vehicle finance in December and the banks kept declining to my surprise I was advised to check my credit score. I then went on to require my credit report and it shows that I apparently have an account with Cell C which was opened on 3 December 2015 and the outstanding amount is said to be R2259. I have never used a Cell C sim card or number in my life let alone sign up for a contract with them. I have tried to get help and clarity from Cell C in Klerksdorp and Potchefstroom but I didn't get any. I tried to call the Cell C customer care with no luck, I kept holding for a consultant until I gave up. I want Cell C to sort this out asap because it's giving me problems. I want them to clear my name so I can be able to get finance.