Cell C unauthorised debit orders

I'm being debited twice for the amount of R479.10. Sadly, I don't and never had an account with Cell C. The account must have been opened **********ly under my name. The reference number for that debit orders are Cell C SP ******5 another one is Cell C SP ******5. Could you kindly refrain from debiting my acc and properly investigate this matter for its is tarnishing my credit record.