********** debit orders

Over the past three months my husband has had 3 unauthorized debit orders placed on his bank account from MTN without him even being a customer of MTN. It started off as a R7000 debit and has now accumulated to about R30000!! And to date, we have had no luck getting any help from MTN regarding the matter. We have phoned the ***** department every month since all of this started and NOTHING is happening to stop this.