Failure to resolve my complaint

Got a call from Telkom when I due for an upgrade and then was sent an incorrect pocket WiFi. I called them to have the device collected which they did and now every month I’m debited, when I call the customer care they give me different stories. First they told me it’s due to a system error and one even hung up on me while talking. I feel so inconvenienced that I’m required to go to the police station for an affidavit in the mean time they keep debiting my account, bare in mind my bank charges me for every reversal