MTN ***** not being dealt with at the clients expense

My husband received notification of a ********** subscription in his name on his MTN account and reported this to MTN immediately on 4 January 2021. MTN did not address this and the new account was debited off my husbands bank account at the end of January. He has subsequently reported this to MTN ***** and this has not been resolved. 16 days later he went into a store to try resolve this and they require him to do an affidavit in order to START the investigation. Nothing has been done to cancel the subscription or to refund him. We can't get any response from MTN South Africa