Cellc debits pre paid customers

My husband formerly held 3 contracts with Cell C but due to them over debiting his account every month we decided to close the accounts with them in July this year, we had paid all the contracts up in full, every last cancelation fee was paid to Cell C, this morning 01 September we woke up to find my husband's bank account had been debited by Cell C of up to R3495.00, when calling their call centre centre he was informed that he was not a contract holder and was told to wait on the line, after waiting he was informed that this was a cancelation fee????? But who authorized this? Cellc never had the permission to take money out of his account!! He paid next to R10 000.00 to get rid of their accounts as every month they would do this to us, and out of no where they ***** from his bank account in the name of a cancelation fee, we are going to the police station this morning to lay a charge of theft and going to FNB to have a block order placed against Cell C.