Telkom Mobi - UNAUTHORIZED DEBIT ORDER

An amount of almost R 11k went off my husband's account for a Telkom Mobi. He is at FNB, but the number when you go into the payment information is from Nedbank. First of all... We don't have a Telkom line. Second my husband has NO agreement with Telkom Mobi which give them authorization to deduct money from his account. Now he has to pay fees to get it reversed and there are fees involved each month for the "debit order" not to go off on his account. A debit order that he NEVER gave permission to and for a Telkom Mobi account he does NOT have. FNB just say we should contact Telkom and sort it out. How do you do that if you don't have an ACCOUNT. Is this not *****?