Unauthorised debit order

One of your agents phoned my elderly mom and said you were from DSTV and that she would get a new decoder delivered as the old one is outdated. Other benefits were also mentioned. After the call ened she got a sms to say that due to credit check it was not approved. On the 30 of May you still pulled off a debit order even though it was not approved. I would like to get that debit order cancelled and the money refunded to her.