Cell C nonsense company and ******

This company is affecting my credit profile because it reflects that i owe them a R 400 that i dont know from where because i have never had a contract with them, i have called them numerous times and i am not getting any assistance from instead they keep taking my number and saying they will call back but they never do instead i keep calling them myself and no help. this is affecting me badly and i ****ed by this company honestly. This is nonsense