Unauthorised Deductions and Disgusting Service

My sister had the most disgusting service from the Unlimited call centre agent. Her account has been deducted for some policy however she has never signed any documents for a policy with this company. She called in this morning to the customer care centre and was assisted by a guy who shouted at her the more she tried to tell him that she is not aware of this policy and unauthorised deductions that is taking place on her account. The same thing happened to me as well. This is *****ulant as nothing was signed. She would like the money to be paid back to her immediately . A response it needed urgently. Thank you